Luke 20:20 KJV
And they watched him, and sent forth spies, which should feign themselves just men, that they might take hold of his words, that so they might deliver him unto the power and authority of the governor.
They "feigned themselves just men." They likely could justify their lie because they believed they were right (just).
I am afraid churches are filled with people who feign themselves just. By far the greater number of them has deceived themselves and believe they are just. They see themselves as righteous and they see themselves as right, even when they take up a cause against the work of the Lord. They are not justified before God, but they are just in their own eyes.
But the Bible gives the true record, Jesus perceived their craftiness and God never fails to see who is truly just and who merely feigns the same. Since our nature is to see ourselves as just men we are dependent upon the Lord to reveal to us what He perceives is the truth about us.
It is not in the asking of questions about the details of religion we will find the answer for justification; it is in listening to the Lord as He searches out our heart.