Then the men were exceedingly afraid, and said to him, "Why have you done this?" For the men knew that he fled from the presence of the Lord, because he had told them."
Jonah 1:9-10 (NKJV)
One meaning of the word hypocrite is, "a person who acts in contradiction to his or her stated beliefs or feelings", someone who says one thing, but does another. The things we say should not be totally different from what we do, there should be an alignment of our words and actions. For example, if we just talk about doing something, or we say we are committed to or believe in something, but our actions are different than what we say, there is a problem.
God told Jonah to go to Nineveh and preach to the people there. But, instead of doing what God said, Jonah disobeyed and sailed away in the opposite direction. Then, when a storm arose, Jonah told the men on the ship how he had disobeyed what God told him to do, but Jonah also said he was someone who "feared God". On the one hand, Jonah talked about serving God, and on the other hand, Jonah would not do what God told him to do, Jonah's words and actions were not aligned.
Paul wrote to Titus about the same problem that Jonah had, how some people profess to know God, but what they do does not agree with what they say. If we really believe something, and for Christians this would be believing in God and His Word, it should have an impact on how we live and what we do. We need to be sure that what we say and do is in alignment with what we believe. This is beneficial for us, and for the people around us who hear what we say and see how we live.