How religious can we be and still be sinful?

How religious can we be and still be sinful? Matthew 27:3 tells us that “When Judas, who had betrayed him, saw that Jesus was condemned, he was seized with remorse and returned the thirty silver coins to the chief priests and the elders.” The religious leaders were unconcerned with Judas’ admission of sin. They didn’t seek to restore him. In fact, they essentially told him that his sin was his problem. Throwing down the pieces of silver, he left and took his own life. Taking up the pieces of silver, the priests admitted the money had purchased a murder. But instead of concern over the sin that they had initiated, facilitated, and purchased with the money, they only saw the taint on the money, not on themselves. It was the money that was tainted, so it could not go into the Temple offering. They were concerned about the right religious practice, not righteousness. They somehow did not feel nor see that their evil deeds disqualified them from entering the temple more so than the money was disqualified as an offering for the Temple.

Lord, what religious observances do I follow while I neglect “the weightier matters of the law: justice and mercy and faith”? Forgive me and show me, so I can repent.