What does it mean that salvation is not of man?

The statement that salvation is not of man highlights the biblical truth that human beings have no part in the act of saving themselves; it is entirely the work of God. Paul asserts in Galatians 1:1 that he is an apostle not sent by man, but by Jesus Christ and God the Father. This reinforces that salvation comes from divine initiative, purpose, and execution. Any human effort or merit added to salvation undermines the grace of God and the completeness of Christ's atonement, asserting that redemption is purely God's gift to the undeserving.