"For I say unto you, That except your righteousness shall exceed the righteousness of the scribes and Pharisees, ye shall in no case enter into the Kingdom of Heaven." (Matthew 5:20)
So just try harder?
Black is black and white is white. Good and evil. Sure, you have the "anti-hero" and "necessary evils" and moral shades of gray that color the plots of books and movies and life. Things can get so screwed-down (as in tightened) and also screwed-up that you are hard-pressed to know which way is which. But Jesus is speaking in the above verse of a standard of living that, while he calls it our own ("except your righteousness..."), must be received from God in order for it to mean anything. Because I can't muster the righteousness required to enter the "Kingdom of Heaven" on my own.
"Jesus answered and said unto him," (He's talking to Nicodemus), "Verily, verily I say unto thee, Except a man (or woman) be born again, [they] cannot see the Kingdom of God." (John 3:3)
So after we receive Jesus--believing that His death and resurrection paid for our sins--then comes the hard and practical work of overhauling our insides and with His help, attuning our minds to a way of thinking that's in line with Him. Because outer morality essentially means nothing when the person exhibiting it has a mind to do their own thing in spite of the way they behave. They're fooling everyone but God.
"For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts." (Isaiah 55:9) This is God speaking. It's the kind of proclamation that's intended to get us to give up. Not to give up on believing in God and that He's more real than we, no. It's the kind of proclamation that is intended to get us to cease striving on our own to reach the standard of holiness that ends in simply erasing our fears about death and hell. Jesus did that already. And with His resurrection the gift of eternal life and also life "more abundantly" (John 10:10) is ours for the asking. "Please" and "thank-You" work wonders with God. He's standing by to give it to you.
How many shades of gray?
"Non-conformity is the highest evolutionary attainment of the social animal." Aldo Leopold, from his book The Sand County Almanac.
I'd have to agree with him but only up to a certain point. Because self-actualization without God is, in my opinion, impossible. It's more than simple non-conformity. When we choose to want to "be ourselves" and yet the motive to do so stems from our disdain for society-at-large, we aren't vaulting from the highest point available to us. "Though the Lord be high, yet hath he respect unto the lowly: but the proud He knoweth afar off." (Psalm 139:6) God is the one who made me. Yes, I have inklings of dreams and desires. Things I'd like to do and see done. But unless I align myself with God and His overarching will, I will never become the fullest version of myself. When my parents divorced I went through and came out of a serious "dark night of the (my) soul". One of the phrases that was borne out of that period was "I'm not who I thought I was". I became someone with reference to God. Now, that's not to say that I never act in accordance with the black or even with an old self-righteousness (white). Far from it. I'm still human. The thing that tells though is both the active realization that God loves me (something that I could never grasp on my own--where would I look for that?) plus a non-chalant, almost cavalier, confidence that took the place of caring about whether or not I sinned. God's love is so much greater than our sin, than our righteousness, than black, than white.
"And His raiment became shining, exceeding white (Luke's Gospel calls it "glistering"--9:29) as snow; so as no fuller on earth can white them." (Mark 9:3)
Peter, James and John got a glimpse of who Jesus really was (and is) when on the mount of transfiguration. Jesus is calling people to a higher standard of holiness. It isn't "holier than thou", it's "I don't even care about how holy I am, I care about Jesus". It's His holiness, His whiteness. And His spectrum.
"The Lord will perfect that which concerneth me: Thy mercy, O Lord, endureth for ever: forsake not the works of thine own hands." (Psalm 138:8)
"Purge me with hyssop, and I shall be clean: wash me, and I shall be whiter than snow." (Psalm 51:7)