There are three requirements for sin to be mortal: grave matter, full knowledge, and deliberate consent. Artificial contraception is intrinsically evil (CCC, 2370) and thus, grave matter. If one deliberately consents to the practice of artificial contraception, knowing of its gravity, then one would be guilty of mortal sin and, without repentance and forgiveness, could “go to hell”. “f [mortal sin] is not redeemed by repentance and God’s forgiveness, it causes exclusion from God’s kingdom and the eternal death of hell…” (CCC, 1861)
