In Jeremiah it says, "The heart is deceitful above all things, and desperately wicked; who can know it? I, the Lord, search the heart, I test the mind, Even to give every man according to his ways, According to the fruit of his doings” Jeremiah 17:9-10 (NKJV).
In 2 Corinthians it says, Satan himself transforms himself into an angel of light. Therefore it is no great thing if his ministers also transform themselves into ministers of righteousness, whose end will be according to their works” 2 Corinthians 11:15 (NKJV).
Make sure your righteousness is done for the right reason.