"Thou blind Pharisee, cleanse first that which is within the cup and platter, that the outside of them may be clean also." -Matthew 23:26, KJV.

So often, we as Christians try to make ourselves look good on the outside to those around us. However, God expects us to treat it the exact opposite way. We are supposed to get our hearts clean first, and, as we clean our inside, the outside will simply follow. It is a lot easier to witness to someone if you truly love them and are following God, but it is very hard to witness to someone just because you know you should.