I have just finished studying Titus, written by Paul to Titus in the island of Crete and according to John Stott the theme of this letter is simply,'' Doctrine and duty''. J Stott ,gives an outline of the Christian Life.
Doctrine and duty in the church][1 V5-16]
 Doctrine and duty in the home[2v1-15]
[3 ]Doctrine and duty in the world [3v1-11]
Doctrine just means a set of beliefs, everybody has some sort of belief , even an atheist is ruled sort of belief, Stalin believed in the teaching of Marx,So we have a world that is full of different beliefs. Because humanity disobeyed God, and went there own way, and so we have a world that has chosen to not worship or follow God. Israel of old was used by God ,to be a witness for Him, they had Gods word, which taught them the right way, as to God Himself, and His will. Those scriptures promised that a Saviour would come, the Jews for all of their history believed this ,and of course He did come in the person of Jesus. He declared that He was the truth and the life ,the only way to God the Father[John 14 v6 ].To know God we must know Jesus, the question you may ask is why?. Because He said so, because only in Him can the barrier of sin be dealt with, only when it is dealt with can we have a relationship with a Holy God.
Dear God help us to see the importance of doctrine, as revealed in your word, in Jesus name we ask this Amen.