Question:
Are there any guidelines for bringing a Christian back to the Lord, or should we just pray?

Answer:
2 Corinthians 10:3-5 gives guidelines: “For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ.” – We don’t have to figure this out in our own wisdom. There is power from above to help us come back to the Lord.

Galatians 6:1 tells us to “restore” such a one using meekness and love to help him come back to the Lord. Matthew 18:15-18 is instruction given to the assembly but can be applied to anyone who is a brother who is sinning. If we are aware that a friend is living in sin, we should go to him. He might turn on you, but this is where the meekness comes into the picture. If he does not listen to you and stop his sinful ways we cannot have happy fellowship with him—1 Corinthians 5:9-11.