Matthew 5:13-16
13 "You are the salt of the earth; but if the salt has become tasteless, how will it be made salty again? It is good for nothing anymore, except to be thrown out and trampled under foot by men. 14 "You are the light of the world. A city set on a hill cannot be hidden. 15 "Nor do men light a lamp, and put it under the peck-measure, but on the lampstand; and it gives light to all who are in the house. 16 "Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven. NAS
There are times when what you do is a better witness than what you say. Maintaining a positive attitude, which can be seen by others even when you are being mistreated for you faith demonstrates the power of the indwelling Holy Spirit.