I think understanding this saying is of paramount significance in order to open a window to the original beliefs of the very same heretical tradition. It is enough to begin by noting that Luke merely speaks of a 'corrupt' tree and a 'corrupt' fruit while Matthew strangely introduces the notion of 'evil' fruit. At first glance it would seem that it makes more sense to speak of 'rotten' fruit than 'evil' ones. Indeed there endless examples of Greek writers speaking of fish, fruit, wood and the like which are 'sarpos' rather than 'poneros.' Yet does this decide the issue of originality?
I think we have been so preconditioned to think in terms of the 'sin' of the Fall and 'sin' as 'evil' that the 'evil fruit' concept comes quite naturally to us. But what is Matthew doing preserving the 'evil' fruit reading rather than Luke? We have also been preconditioned (I mean the scholarly or pseudo-scholarly minds) to think in terms of the Marcionite juxtaposition between the 'good' and 'evil' gods that we assume that this must have been the Marcionite reading too. Yet this doesn't solve the more fundamental question of Matthew rather than Luke preserving the supposed Marcionite reading.
The fact that Tertullian (or his source) preserves not only the same alleged Marcionite understanding but twice - in two separate 'books' no less - draws in the same supporting argument from Isaiah 45:7 implies to me at least that he is citing from a very early 'proof text' of some sort against the Marcionites. The fact that Alan Segal sees parallels with the rabbinic arguments against the 'two powers' heresy may even suggest a pre-Christian origin for the 'proof text.' Let's site the anti-Marcionite arguments in their original context to see what is really going on here.
Tertullian (or his source) originally says - undoubtedly drawing from knowledge of a 'letter' of Marcion mentioned in De Recta in Deum Fide (Adamantius) and dealt at great length by a fascinating but ultimately ignored paper by Harris says:
The heretic of Pontus introduces two Gods, like the twin Symplegades of his own shipwreck: One whom it was impossible to deny, i.e. our Creator; and one whom he will never be able to prove, i.e. his own god. The unhappy man gained the first idea of his conceit from the simple passage of our Lord's saying, which has reference to human beings and not divine ones, wherein He disposes of those examples of a good tree and a corrupt one; how that “the good tree brings not forth corrupt fruit, neither the corrupt tree good fruit.” Which means, that an honest mind and good faith cannot produce evil deeds, any more than an evil disposition can produce good deeds. Now (like many other persons now-a-days, especially those who have an heretical proclivity), while morbidly brooding over the question of the origin of evil, his perception became blunted by the very irregularity of his researches; and when he found the Creator declaring, “I am He that creates evil,” [Isaiah 45:7] inasmuch as he had already concluded from other arguments, which are satisfactory to every perverted mind, that God is the author of evil, so he now applied to the Creator the figure of the corrupt tree bringing forth evil fruit, that is, moral evil, and then presumed that there ought to be another god, after the analogy of the good tree producing its good fruit. Accordingly, finding in Christ a different disposition, as it were— one of a simple and pure benevolence — differing from the Creator, he readily argued that in his Christ had been revealed a new and strange divinity; and then with a little leaven he leavened the whole lump of the faith, flavouring it with the acidity of his own heresy. [Adv Marc 1.2]
For if He who has this attribute is the Most Good, you will have first to relinquish that position of yours, that the very contact with evil is incompatible with such a Being, that is, with the most good God. And because Marcion, too, maintains that a good tree ought not to produce bad fruit; but yet he has mentioned “evil” (in the passage under discussion), which the most good God is incapable of, is there forthcoming any explanation of these “evils,” which may render them compatible with even the most Good? There is. We say, in short, that evil in the present case means, not what may be attributed to the Creator's nature as an evil being, but what may be attributed to His power as a judge. In accordance with which He declared, “I create evil,” Isaiah 45:7 and, “I frame evil against you;” Jeremiah 18:11 meaning not to sinful evils, but avenging ones. What sort of stigma pertains to these, congruous as they are with God's judicial character, we have sufficiently explained. Now although these are called “evils,” they are yet not reprehensible in a judge; nor because of this their name do they show that the judge is evil: so in like manner will this particular evil be understood to be one of this class of judiciary evils, and along with them to be compatible with (God as) a judge. The Greeks also sometimes use the word “evils” for troubles and injuries (not malignant ones), as in this passage of yours is also meant.[ibid 2.24]
Sebastian Moll wrote one of the most wretched works ever penned on the subject of Marcionitism. While he claims Harnack misrepresented the evidence, a careful reading of the argument even here makes clear how hopeless the argument for a strong dualistic interpretation of the sect is impossible.
Marcionitism was not about the juxtaposition between a 'good god' and an 'evil god' but - as we see here - a theory centrally focused on the question of the origin of evil. With respect to the question of 'the evil fruit' it becomes plain that the parable of the two trees is developed to distance the Father (the 'good tree') from the Logos (the 'corrupt tree'). We see this clearly in another passage in these first books of Against Marcion:
The goodness of God having, therefore, provided man for the pursuit of the knowledge of Himself, added this to its original notification, that it first prepared a habitation for him, the vast fabric (of the world) to begin with, and then afterwards the vaster one (of a higher world, ) that he might on a great as well as on a smaller stage practise and advance in his probation, and so be promoted from the good which God had given him, that is, from his high position, to God's best; that is, to some higher abode. In this good work God employs a most excellent minister, even His own Word. “My heart,” He says, “has emitted my most excellent Word.” Let Marcion take hence his first lesson on the noble fruit of this truly most excellent tree. But, like a most clumsy clown, he has grafted a good branch on a bad stock. The sapling, however, of his blasphemy shall be never strong: it shall wither with its planter, and thus shall be manifested the nature of the good tree. Look at the total result: how fruitful was the Word! God issued His fiat, and it was done: God also saw that it was good; not as if He were ignorant of the good until He saw it; but because it was good, He therefore saw it, and honoured it, and set His seal upon it; and consummated the goodness of His works by His vouchsafing to them that contemplation. Thus God blessed what He made good, in order that He might commend Himself to you as whole and perfect, good both in word and act. As yet the Word knew no malediction, because He was a stranger to malefaction. We shall see what reasons required this also of God. Meanwhile the world consisted of all things good, plainly foreshowing how much good was preparing for him for whom all this was provided. Who indeed was so worthy of dwelling among the works of God, as he who was His own image and likeness? That image was wrought out by a goodness even more operative than its wont, with no imperious word, but with friendly hand preceded by an almost affable utterance: “Let us make man in our image, after our likeness.” Genesis 1:26 Goodness spoke the word; Goodness formed man of the dust of the ground into so great a substance of the flesh, built up out of one material with so many qualities; Goodness breathed into him a soul, not dead but living. Goodness gave him dominion over all things, which he was to enjoy and rule over, and even give names to. In addition to this, Goodness annexed pleasures to man so that, while master of the whole world, he might tarry among higher delights, being translated into paradise, out of the world into the Church. The self-same Goodness provided also a help meet for him, that there might be nothing in his lot that was not good. For, said He, that the man be alone is not good. He knew full well what a blessing to him would be the sex of Mary, and also of the Church. The law, however, which you find fault with, and wrest into a subject of contention, was imposed on man by Goodness, aiming at his happiness, that he might cleave to God, and so not show himself an abject creature rather than a free one, nor reduce himself to the level of the other animals, his subjects, which were free from God, and exempt from all tedious subjection; but might, as the sole human being, boast that he alone was worthy of receiving laws from God; and as a rational being, capable of intelligence and knowledge, be restrained within the bounds of rational liberty, subject to Him who had subjected all things unto him. To secure the observance of this law, Goodness likewise took counsel by help of this sanction: “In the day that you eat thereof, you shall surely die.” [Genesis 2:17] For it was a most benignant act of His thus to point out the issues of transgression, lest ignorance of the danger should encourage a neglect of obedience. Now, since it was given as a reason previous to the imposition of the law, it also amounted to a motive for subsequently observing it, that a penalty was annexed to its transgression; a penalty, indeed, which He who proposed it was still unwilling that it should be incurred. Learn then the goodness of our God amidst these things and up to this point; learn it from His excellent works, from His kindly blessings, from His indulgent bounties, from His gracious providences, from His laws and warnings, so good and merciful. [2.4]
What has completely eluded Moll and countless other commentators is the fact that the real controversy is laid bare in this commentary.
It has long been argued that Against Marcion Book Two was developed from a book originally written by Theophilus of Antioch. There are many statements in this work which assume a godhead very much like that of Philo of Alexandria - namely a 'merciful' power, a 'just' power and the Logos. What shocked Theophilus (and what is later obscured by Irenaeus and perhaps other editors including Tertullian) is that Marcion could have suggested that the Logos created gave birth to Satan or the Devil - the former representing 'the corrupt tree' the latter his 'evil fruit.' The original context was then not then a condemnation of the 'corrupt tree' but rather an acknowledgement of his 'original sin' a sin which strangely gets resolved or redeemed through the crucified one hanging from - you guessed it - another 'tree.'
The Pentateuch interestingly does not speak so much about 'fruit' of the tree but rather 'eating' of the tree. To this end, this helps us segue to the next point of contention for the Marcionites - namely that the two trees are about 'natures' (yetzerim sing. yetzer). Eating of the tree caused a change of yetzer into that of 'materialism.' How then did the Marcionites suppose that the tree of life (the Cross) saved people? This is another investigation we can develop subsequently. Nevertheless for the present moment we should recognize that the 'good fruit' is necessarily Jesus or rather the nature of his flesh which is consumed during Christian communion with God (the Eucharist).
There was also clearly an understanding that the 'corrupt tree' was the Law but from here things get rather complicated. If we stop right here and admit that Matthew rather than Luke seems to preserve the original Marcionite gospel reading it is readily apparent how futile it is to simply reconstruct the Marcionite gospel based upon 'variant' readings of Luke (as is typically done in scholarship and pseudo-scholarship). A very interesting question develops as to how the canonical gospels preserved textual readings. How can we continue to believe that this plethora of variants within the canonical gospels simply occurred 'naturally' i.e. 'innocently' through the preservation of pre-existing manuscripts?
The situation seems to reflect a conscious decision to 'park' the correct reading of the Marcionite in Matthew rather than Luke but to introduce alongside the correct reading another which supports the orthodox interpretation of the saying - i.e. Matthew 12:33
Make a tree good and its fruit will be good, or make a tree bad and its fruit will be bad, for a tree is recognized by its fruit
This variant, developed as an addition to the debate with the Pharisees seems to be introduced into the Catholic canon in order to justify what Tertullian (Irenaeus) identifies as the correct interpretation of the saying "that is, that a good mind or a good faith does not produce evil actions, nor an evil mind and faith good ones." (Adv Marc 1:2) In other words, the Marcionite application of the saying to the origin of evil and 'heavenly beings' is wholly invented.
The saying must have existed at one time in a loose collection of 'sayings of Jesus' perhaps in a form like that of the Gospel of (Judas) Thomas. The editor of the Catholic canon seems to have gone back to that assumption to invent a new context which 'proves' the orthodox application of the saying to an inner 'spiritual' context rather than the original 'mystic' cosmic application. In any case the application of a saying in this time of 'debate' context is clearly secondary given the presumed existence of a 'collection of sayings' which preserved only the bare words of the Christian 'savior.'
The fact that the Catholic canon was developed specifically to provide context fro enigmatic sayings such as this is quite significant. It calls into question the typical manner of reading the gospels 'innocently' as if they simply preserved the sayings and doings of Jesus. The idea then that Matthew not only preserved the original Marcionite reading and moreover a second 'historical context' to the saying (i.e. the debate with the Pharisees) seems to imply to me that the canon was itself developed in a very sophisticated manner with the end purpose of vanquishing the heretical tradition.
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."