Will God ever tell a believer that salvation wasn't what it seemed to be?
No. A believer will never hear from God that salvation was not what it seemed. At the eternal abode, God will affirm that the blood of Christ is faithful; He is faithful, and that is why we can trust Him. It is not how much we love Him, but how much He has loved us.
Les teaches from the chair illustration that people sit down without inspecting the chair, placing faith in it to hold them; for it to do so, the chair must be faithful. In the same way, Christ has claimed to have done everything necessary, and the teacher put his faith in that. Les says that at the eternal abode, God will not say, “I’m sorry, it wasn’t what it seemed to be.” Instead, He will say the blood of Christ is faithful; He is faithful, and that is why we can trust Him. This is what Paul is driving at: faith in the One who is faithful to keep us, because He loved me and gave Himself for me. A young grandson asked whether he loved God enough or had enough faith not to be left behind. Les explains it is not how much we love Him, but how much He has loved us.