Do you seriously think God didn't fully inform the person upon whom the future of the human race depended about his and mankind's redemption?
how much of the gospel can you intuit from 'he will bruise His heel, but He will crush his head'?
Ephesians 3:8-9
To me, who am less than the least of all the saints, this grace was given, that I should preach among the Gentiles the unsearchable riches of Christ, and to make all see what [is] the fellowship of the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ