Human nature
Irenaeus’ conception of salvation relies heavily on the understanding found in Paul's letters. Irenaeus first brings up the theme of victory over sin and evil that is afforded by Jesus's death. God's intervention has saved humanity from the Fall of Adam and the wickedness of Satan. Human nature has become joined with God's in the person of Jesus, thus allowing human nature to have victory over sin. Paul writes on the same theme, that Christ has come so that a new order is formed, and being under the Law, is being under the sin of Adam.