Hebrews 13:21 (NKJV)
Were you ever with a group of people who were trying to decide on something, and there did not seem to be any agreement about that thing? Often in these situations there are differences of opinion, because each person has their own ideas and their own desires about what they want to do. The only way anything gets accomplished is if some people yield to the desires of someone else rather than insisting on doing what pleases them; they do what someone else wants instead of what they might want.
In Hebrews 13, there is what might be called a prayer, or a benediction, where it talks about God making someone complete (meaning equipped) in every good work to do God's will, and working in them what is well pleasing in His sight. This is something that every Christian should want to do, to live a life that pleases God and fulfills His will. Other places in the New Testament talk about living a life that fully pleases God (Colossians 1:10) and that our goal should be to please God (2 Corinthians 5:9).
Our goal as Christians should be to live a life that is well pleasing to God, but it is easy to see that some believers have a greater interest in living a life that is well pleasing to themselves. While God does not want us to be unhappy and live like we are His slaves, with no will or desires of our own, living a life that is well pleasing to God means that we must make His will our will, no matter what that means for our plans and desires. If our goal is to please God, it can mean that there will be times we must yield to His will instead of ours.