Why did Jesus tell the rich young ruler to keep the commandments if we are not under Law?
Jesus told the rich young ruler to keep the commandments because that encounter belonged to the Law program for Israel, not the present grace program. It is not a contradiction but a change in God's modus operandi: today the message is to believe the Gospel.
Les explains that the rich young ruler came to Jesus asking what he must do for eternal life, and Jesus answered, keep the commandments. That was appropriate because Jesus was speaking to the Jew under the Law. It is not a contradiction with the grace message. Les teaches it is a change of program: we are not under Law, we are under grace. Today Jesus would not write to us to keep the commandments; today the message is to believe the Gospel. The apparent conflict is resolved by recognizing God's change in modus operandi.