“You have need of perseverance,” the author of the letter to the Hebrews urges his audience (10:36). But why?
This past weekend during the first week of class, we were talking about the truth that God saves sinners. (This teaching is put forth in what has somewhat unfortunately become called the Five Points of Calvinism.) When we were talking about the doctrine of the Preservation of the Elect (a.k.a. Perseverance of the Saints), Dr. Griffith asked us, “Why is perseverance in faith necessary? Why can’t we just be justified at some point upon making a ‘decision for Christ’ and then live as we please?”
"Our Lord Jesus Christ . . . will keep you strong to the end, so that you will be blameless on the day of our Lord Jesus Christ. God, who has called you into fellowship with his Son Christ Jesus our Lord, is faithful." (1 Cor. 1:8-9)
 John Murray, Redemption Accomplished and Applied (