False Christians don't have a heart to lead someone to Christ or confess the Lord before others (Matt. 10.32-33). Only if asked by a Christian will they respond they believe because they know that's what the Christian wants to hear. They did not mention Christ all these years you knew them, nor did they rejoice when you yourself got saved. They have no passion for Christ. It is as though Jesus is dead and stayed dead to them. When you know those who are unsaved close to them, they have never tried to lead them to Christ either. They don't read the Bible. Their only friends are non-Christians. After you got saved and tried to lead them to Christ they remained hostile, but over time did an about face. They changed their story and introduced the idea their confirmation as a child just because one time they remember going to Church as a child. They don't go to Church. They have no fellowship with the body of Christ. Even when talking to them still all their opinions are so contrary to the spirit of Scripture. Along the way they may mention belief in reincarnation or that one should not mention hell. It is God’s decision they say. They may claim you can’t repent and believe before regeneration. They shut their minds down, busying themselves in the world. There is no budging them. If they really were Christians, the Church would not exist for their participation is non-existent and remains so.