Luke 12:11-12

And when they bring you unto the synagogues, and unto magistrates, and powers, take ye no thought how or what thing ye shall answer, or what ye shall say: For the Holy Ghost shall teach you in the same hour what ye ought to say.

God always gives us what we need. This includes words. When we go out to talk to people we should allow God to give us the words that he wants us to use, not make up our own. This is very comforting in the fact that we don’t have to have everything committed to memory, we just need to have an understanding of his word and the faith that he will give us what we need when we need it.