I. Another tree (by which, as a sacrament, God wished to seal the promise given) was the tree of life. Regarding this name opinions differ.
Why called “the tree of life”? Not effectively.
II. Some maintain that it was so called effectively because it had an innate power of vivifying man (i.e., of keeping off not only diseases and weaknesses, but also death itself) and of conferring upon him absolute immortality (the opinion of Bellarmine and other papists, but deservedly rejected by Scotus, Thomas Aquinas and others). A finite power could not have an infinite efficacy of extending life to an infinite time. Besides, since its fruit no less than its sap was liable to corruption, it could not absolutely free man from destruction, unless another cause intervened. It can indeed be determined probably that its fruit was the best and most efficacious aliment for preserving life (having the power of strengthening the nutritive faculty, repairing the weak radical and preserving an equable state of health and vigor) until it should be carried to the heavenly life. Yet on this account, it ought not to be distinguished by this peculiar name because other trees also had the same power, if not equal strength.
III. Far better therefore is the opinion of others that the tree obtained this name principally by reason of signification. It was a sacrament and symbol of the immortality which would have been bestowed upon Adam if he had persevered in his first state. Augustine says, “He had nourishment in other trees; in this, however, a sacrament” (The Literal Meaning of Genesis 8.4 [ACW 42:38; PL 34.375]). Now this signification can have a threefold relation (schesin). (1) With respect to past life, it was a symbol putting him in mind (mnēmoneutikon) of the life received from God. As often as he tasted its fruit, he was bound to recollect that he had life not from himself, but from God. (2) With respect to future life, it was a declarative (sēmantikon) and sealing (sphragistikon) sign of the happy life to be passed in paradise and to be changed afterwards into a heavenly life, if he had continued upright. (3) With respect to the state of grace, it was an illustrious type of the eternal happiness prepared for us in heaven; also a type of Christ himself who acquired and confers it upon us and who is therefore called “the tree of life in the midst of the paradise of God” (Rev. 2:7); “the tree of life yielding her fruit twelve times every month, whose leaves are for the healing of the nations” (Rev. 22:2).
IV. Therefore the life which this tree signified and sealed was not properly either the longevity or the immortality of the body alone; rather it was the eternal happiness to be obtained at length in heaven (which comes under the name of eternal life in Scripture and which no food can impart, but with which the use of food and drink rather contends). Hence it is said that God will abolish both the stomach and food, so that man may see God not in this animal body, but in a spiritual. This will be proved hereafter in a separate question.
V. When God expelled man from paradise “lest man put forth his hand, and take also of the tree of life, and eat, and live for ever” (Gen. 3:22), it cannot thence be rightly inferred that there was a physical power in this tree of so great efficacy that it could (its fruit having been once tasted) rescue even sinful man from mortality. These words denote only the cause of his ejection from paradise on account of sin (by which, as by his own fault, he had cut himself off from that life, which was the thing signified). Thus he ought no longer to have any right to its sacrament. God speaks not with reference to the thing itself or its event (as if that tree would actually preserve his life even after sin), but in relation to the preposterous opinion of Adam who could think this, not understanding the true reason of the name. That he might not, therefore, endeavor (though vainly) to render void the threatening of God, he is expelled from paradise. Not that God envied the immortality or the longer life of man, but because it was not right that he should longer enjoy the sign of the immortality which he had lost. For this purpose he also willed to station the cherubim with a flaming sword at the gate of paradise in order that our first parents might be kept away as much from the garden as from the tree.
How did the tree of life signify Christ?
VI. What was interdicted to them in that pristine state is now not only made lawful to us, but also commanded and promised in the state of grace (in which easy access is given to us to the heavenly paradise and to Christ, the true tree of life). This is the truth and mystery shadowed in this ancient type: the tree of life—not earthly, but heavenly; not material and irrational (alogos), but mystical and rational; not only significative and sealing of life, but truly the bestower of it. “In him was life” (Jn. 1:4, i.e., the fountain and cause of all life). This life is as much natural in the world (because in him we live and move and have our being, Acts 17:28), as spiritual in the church through grace (because as Mediator, he is the prince of life giving life to the world and eternal life in heaven by glory; for he is “the resurrection and the life” who will most certainly bestow upon his own eternal life). Truly he is the only tree because no one except Christ is the author of eternal life (nor is there salvation in any other, Acts 4:12). No one except Christ is in the midst of paradise (Rev. 2:7) and of the street of the city (Rev. 22:2). Christ is in the midst of the church (as a more honorable and suitable place) to be near all and diffuse his vivifying power among all; to be seen by all, as the center in which all the lines of faith and love ought to meet, that they may acquiesce in him. The fruit-bearing tree (Rev. 2:7), which bears the sweetest and most exquisite fruit for the support of believers (Cant. 2:3), bears twelve kinds of them (Rev. 22:2), i.e., the most abundant and richest, sufficing for the twelve tribes of Israel (i.e., for all the members of the church, which from his fullness draw all gifts necessary for them). It bears them every month (i.e., perpetually) because the power and efficacy of the righteousness and spirit of Christ are perpetual and unceasing for the consolation and sanctification of believers. Its leaves (never falling and perpetually green) are appointed for the healing of the nations because it has the virtue not only of aliment (to feed our souls), but also of medicine (most healthful to cure all our diseases, Is. 53:5; Mt. 11:28).
VII. Hence it is evident that these two trees of paradise are not free from mystery. For as the first was a sacrament of trial (which prescribed to man his duty) and the second a symbol of the reward (by which God wished to remunerate his obedience), so each shadowed forth to us in the best manner, the mode of God’s acting in the church by commands and promises. The former prescribed to man his duty and explored his obedience (well signified by the tree of the knowledge of good and evil). The latter exhibited the blessing and most ample reward of God by which he wishes to crown our obedience (fitly expressed by the tree of life). Second, the law and the gospel can also be contained under this double symbol. For the law (as the tree of the knowledge of good and evil) is given to us as a trial of obedience and by sin (no less than that) is made the occasion of death and the minister of condemnation. The gospel, however, is the saving and quickening tree of life because it is “the word of life” (Jn. 6:68). Third, the former exhibits the image of Adam from whom sin and death flowed; however the latter exhibits Christ from whom righteousness and life arise (1 Cor. 15:22).
ACW Ancient Christian Writers. New York: Newman Press, 1946–.
PL Jacques Paul Migne, Patrologiae … series Latina. Paris: Garnieri Fratres, 1878.