We don't become a follower of Christ by saying the sinners prayer anymore than we become a Big Mac by saying "2 all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun." The sinners prayer is a good "jumping off place" but it's not what makes us His. We must recognize that we are a sinner in need of a Savior. We must repent.
As for Ray, he has never taught this is all we have to do. Ironic notion since he regularly gets grief for his use of the Law.
But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. (Romans 10:8-10 KJV)
If.... thou shalt be saved.