“‘These people honor me with their lips, but their hearts are far from me. They worship me in vain; their teachings are but rules taught by men.'” -Matthew 15:8,9 (quoting Isaiah 29:13)
One of the most important lessons to take from Jesus’ teaching, if the first testament was not clear enough, is sincerity. In faith, sincerity is paramount. Even if, by discipline, you discover your own insincerity, your task is to move beyond it by identifying it and confessing it to your Father.
For instance, prayer almost always reveals something I am insincere about. Whether something from my community with other Christians, or even something I’ve been praying to God for, it’s hard to spend a long time in prayer without being disturbed at my self-dishonesty for at least some of the time.
But that should not stop me from praying. And it should definitely not stop me from making a request. What it should stop me from doing is thinking that those good desires come from me; it should stop me from pretending that I deserve salvation.
And in the end of that pretending, the grace of God reaches a height that it couldn’t otherwise. When I stop persuading myself that I am right, God becomes even more right for me.