day no. 17,284: the outside of the cup isn't irrelevant

"True worship is what occurs when we come to worship God, with all the externals established in true obedience, and all the internals lined up to match. Clean the inside of the cup, the Lord said, but He did not say that the outside was irrelevant. He said that then the outside would be clean also." — Douglas Wilson, No Jesus, No Way (Amos 5:1-17)

Because we tend to put more emphasis on what others can see than on what only God can see, we focus more on the outside of the cup than on the inside. We can get people off our backs if we keep the outside of our cups clean. And so, this is why Jesus placed an emphasis on the inside of the cup.

Matthew 23:25-26

Woe unto you, scribes and Pharisees, hypocrites! for ye make clean the outside of the cup and of the platter, but within they are full of extortion and excess. Thou blind Pharisee, cleanse first that which is within the cup and platter, that the outside of them may be clean also.

The Pharisees were notorious for being overly scrupulous when it came to the outside of their cups and under interested when it came to the inside. So, man-pleasers should take note: it isn't merely what you look like, but what you are that counts. 

That said, Jesus did not dismiss the outside of the cup. Too many in their zeal to apply this passage make it say more than it does. Jesus did not make the outside of the cup irrelevant. The inside and the outside of the cup are not pitted against each other. They should both be cleaned. You should live your life in such a way that men who see you praise your God and God who sees your inner man delights in why you are doing what you are doing.