Not only do you need to understand the utter sinfulness of man, you need to understand the absolute holiness of God. In Isaiah 6:3And one cried unto another, and said, Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory.
See All... the seraphim cried out, Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory. Holiness means that God has no blemish, or evil, or wickedness. Everything is pure, holy and righteous with God. He shines with a brilliant light that would strike us down and destroy us the very second we saw Him. He is that pure and that holy. 

Habakkuk 1:13Thou art of purer eyes than to behold evil, and canst not look on iniquity: wherefore lookest thou upon them that deal treacherously, and holdest thy tongue when the wicked devoureth the man that is more righteous than he?
See All... says, “Thou art of purer eyes than to behold evil, and canst not look on iniquity: wherefore lookest thou upon them that deal treacherously, and holdest thy tongue when the wicked devoureth the man that is more righteous than he?” God’s eyes are so pure that He cannot even look upon our sinfulness. God is so holy that you and He could not exist in the same universe apart from the grace of God.

Job 25:4-6 [4] How then can man be justified with God? or how can he be clean that is born of a woman? [5] Behold even to the moon, and it shineth not; yea, the stars are not pure in his sight. [6] How much less man, that is a worm? and the son of man, which is a worm?
See All... says, “How then can man be justified with God? or how can he be clean that is born of a woman? Behold even to the moon, and it shineth not; yea, the stars are not pure in his sight. How much less man, that is a worm? and the son of man, which is a worm?”

Even the stars are not pure in God’s sight; the moon is not pure in His sight. How can man be pure in His sight? We are as a worm. You say that this is not good for your self-esteem. But the best thing for you is to destroy your self-esteem. Your esteem ought to be in God and not in yourself. Even expressions of supposed humility may be pride. You do not need to go around saying, “I am a nobody; I am a nobody.” That is an expression of pride. You are proud of your humility. You say, “Wait a minute, you are making everything a sin.” You are getting it; you are getting it! We cannot do anything right in our own strength.

Some people go around with this false humility. The Bible talks about it in Colossians and calls it a “voluntary humility” (Colossians 2:18Let no man beguile you of your reward in a voluntary humility and worshipping of angels, intruding into those things which he hath not seen, vainly puffed up by his fleshly mind,
See All...). Someone who loves God and has given his life to God does not have to act like a throw rug to be stepped on. He stands up tall, walks straight and goes where he is supposed to go because God is in charge of his life. He knows that he is not in charge of his own life. Paul said, “For there stood by me this night the angel of God, whose I am, and whom I serve.” Paul did not go around saying he was a humble Christian all the time. His attitude was more like, “I serve the God of the universe and I have something to say for His sake.” That is not false humility.

You are created by God and your very life depends upon Him. You have no right to live your life as you please. When you get to the point where you realize that you are nothing, but He is everything; that Jesus Christ came and died for you so that He might live in you; then you can begin to realize the joy and the freedom and the liberty and the peace available in the Lord and Saviour Jesus Christ!  We want to hold on to our own righteousness and do what good we can do. We want to hold on to some idea of our own goodness. But any good you have is God in you! If He is not in you, then there is no good in you.