It is good to be good! God commands it. But if a person in seeking God assumes that perfection is attainable in this life, that person is deluded. Sin goes too deep for us ever to cease our vigilance. We don't know ourselves that well.
Who can say, "I have made my heart clean; I am pure from my sin"?
-- Proverbs 20:9 NRSV.
If we claim to be without sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. If we claim we have not sinned, we make him out to be a liar and his word has no place in our lives.
-- I John 1:8-10 NIV.