Better to presume someone is not saved and be wrong than presume someone is saved and be wrong. I would encourage you to pray and ask the Lord to prepare you and the person. I would then respectfully and lovingly ask them if they are ready to stand before God. If they answer yes, then I would ask them how they got ready to stand before God. If they answer in any way other than how the Bible says then share with them the following. If they answer no or not sure ask them if they would like to be ready. Then share a very simple plan of salvation. (A) Admit that you are a sinner. Romans 3:23. (B) Believe that Jesus is the only way of salvation. John 14:6. (C) Confess Jesus as your Lord and Savior Romans 10:9-10.