Kindness is not simply being nice. It’s courage and discipline, it’s constant and unchanging. It’s a simple facet of Christ, not a smiling face of a Christian. It’s not a performance for the masses, it’s a performance for the audience of one. It does not tire or boast or point to “I,” but is there always, operates in the secret, and points to God. Allow these words to inspire an eternal kindness to permeate the facade of the world’s short pursuit of being nice. 

Or do you presume on the riches of his kindness and forbearance and patience, not knowing that God’s kindness is meant to lead you to repentance? Romans 2:4 (ESV) 

I shall pass through this world but once. Any good thing therefore that I can do, or any kindness that I can show to any human being, let me do it now. Let me not defer it or neglect it, for I shall not pass this way again.
Henry Drummond

Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you.(Ephesians 4:32 ESV) 

Kindness makes a person attractive. If you would win the world, melt it, do not hammer it.