Why do we please the Lord? It shouldn't be because we're trying to gain His favor. We already have His favor. We seek to please Him because we love Him! And even more so because He loves us! Motivation to serve the Lord and please Him should not come out of "guilt!" It should come out of love!
I don't please my wife because I'm trying to "earn" her love. I seek to please my wife because I already have her love! From the day she said, "I do", I had her acceptance and her love. I don't have to try to keep earning her love. If she felt I was doing that she would be offended. And I believe God feels the same way. We shouldn't try to get Him to be happy with us. We should enjoy His pleasure and we should love to keep doing the things we know please Him.