What does Paul teach about the person who does not work but believes on God who justifies the ungodly?

Les explains that Paul is writing after the fact, so he can declare that Christ died for our sin and was risen from the dead for our justification. The one who does not work but believes on the God who justifies the ungodly has his faith counted for righteousness. This is not earned by working; it is received by simply believing what Christ accomplished. Even though Christ had told the twelve He would be put to death and rise the third day, they understood none of it and thought everything was done after He died.