It is a heresy condemned by the Council of Trent to deny that Adam and Eve existed, to deny that we are all their biological descendents, and to deny that we contract original sin by being their literal descendents.
1. If any one does not confess that the first man, Adam, when he had transgressed the commandment of God in Paradise, immediately lost the holiness and justice wherein he had been constituted; and that he incurred, through the offence of that prevarication, the wrath and indignation of God, and consequently death, with which God had previously threatened him, and, together with death, captivity under his power who thenceforth had the empire of death, that is to say, the devil, and that the entire Adam, through that offence of prevarication, was changed, in body and soul, for the worse; let him be anathema.
Whoever obstinately denies or obstinately doubts that Adam existed is rejecting the infallible teaching that Adam, as the first man, transgressed the commandment of God and thereby fell from grace.
2. If any one asserts, that the prevarication of Adam injured himself alone, and not his posterity; and that the holiness and justice, received of God, which he lost, he lost for himself alone, and not for us also; or that he, being defiled by the sin of disobedience, has only transfused death, and pains of the body, into the whole human race, but not sin also, which is the death of the soul; let him be anathema:–whereas he contradicts the apostle who says; By one man sin entered into the world, and by sin death, and so death passed upon all men, in whom all have sinned.
Whowever obstinately denies or obstinately doubts that Adam existed is rejecting the infallible teaching that Adam injured both himself and his posterity by his fall from grace, and that death and the other effects of original sin were tranfused into the whole human race as a result of his fall.
3. If any one asserts, that this sin of Adam,–which in its origin is one, and being transfused into all by propogation, not by imitation, is in each one as his own, --is taken away either by the powers of human nature, or by any other remedy than the merit of the one mediator, our Lord Jesus Christ, who hath reconciled us to God in his own blood, made unto us justice, santification, and redemption; or if he denies that the said merit of Jesus Christ is applied, both to adults and to infants, by the sacrament of baptism rightly administered in the form of the church; let him be anathema: For there is no other name under heaven given to men, whereby we must be saved. Whence that voice; Behold the lamb of God behold him who taketh away the sins of the world; and that other; As many as have been baptized, have put on Christ.
Whowever obstinately denies or obstinately doubts that Adam existed is rejecting the infallible teaching that we need Baptism, merited for us by Christ, in order to be reconciled to God, because of the sin of Adam.
4. If any one denies, that infants, newly born from their mothers’ wombs, even though they be sprung from baptized parents, are to be baptized; or says that they are baptized indeed for the remission of sins, but that they derive nothing of original sin from Adam, which has need of being expiated by the laver of regeneration for the obtaining life everlasting,–whence it follows as a consequence, that in them the form of baptism, for the remission of sins, is understood to be not true, but false, --let him be anathema.
Whowever obstinately denies or obstinately doubts that Adam existed is rejecting the infallible teaching that human persons must be baptized because they are affected by the original sin of Adam, and that Baptism takes away original sin.
If there was no Adam, then:
there would be no original sin
we would not be in a fallen state
we would need Baptism
we would not need to be reconciled to God by Christ
the Immaculate Conception, which preserved Mary from original sin, would be meaningless, null, and void
Whoever denies Adam, denies original sin, Baptism, the Immaculate Conception, and the need for salvation by Christ.