My sister says she made a decision for Christ. Where does this idea come from and are there some verses that I can share with her that show that God has chosen us?
Decision theology results from a rejection of infant baptism and original sin.
The Bible makes it very clear that we cannot bring ourselves to faith in Jesus Christ. For starters, we were spiritually dead people by nature (Ephesians 2:1), having no ability to do anything like deciding to believe in Jesus. Secondly, we were natural enemies of God because of sin and unbelief (Romans 8:7). We would not have wanted to bring ourselves to faith in God even if we had the ability. Finally, the Bible tells us that we were spiritually blind by nature (2 Corinthians 4:4), unable to see the truth about ourselves or God.
Scripture teaches plainly that Christian faith “is not from yourselves, it is the gift of God” (Ephesians 2:8). Jesus’ words to his first disciples apply to us as well: “You did not choose me, but I chose you” (John 15:16). The Holy Spirit is the one who enables us to confess Jesus Christ as our Savior (1 Corinthians 12:3).
Salvation is a gift from God. The faith that makes salvation our own is also a gift from God. God gets all the credit—and praise—for our salvation which we enjoy through faith in Jesus Christ.