God the Holy Spirit turns wanderers back to Himself, but He ordinarily uses people to do so, just as He uses means to bring people to saving faith in the first place. Just as God will use our faithful prayers and proclamation of the gospel for the saving of His elect, He will use our faithful exhortations to backsliders to be the means of reclaiming them. That’s what the Lord did when King David wandered from the truth. The Lord sent Nathan to confront the king and call him to repentance (2 Sam. 12).