How do we know that salvation is not a decision by men?

The assertion that salvation is not a decision by men is grounded in Galatians 1:15, which underscores that God's calling occurs by His pleasure, independent of human efforts. This principle is central to Reformed theology, distinguishing between mere intellectual assent and a genuine heart transformation, which occurs solely by God's initiative. As Paul testifies, he did not choose Christ but was apprehended by Him, demonstrating God's sovereign intervention in the process of salvation (Philippians 3:12).