When God confronted Adam and Eve after their sin in the Garden of Eden, see Genesis 3:1-24, He pronounced a series of curses and punishments; within this God made reference to the coming Christ who was to take away the sin of the world.
“Little children, it is the last hour; and as you have heard that the Antichrist is coming, even now many antichrists have come, by which we know that it is the last hour.” I John 2:18.
“Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life.” John 5:24.