You, however, must teach what is appropriate to sound doctrine.
Titus 2:1 NIV
In this verse, Paul instructed Titus to teach what is appropriate to sound doctrine. If you pull this verse out of its context, it would seem to be saying that the doctrine I teach should be soundly based on the Bible. And while that is true, it is not what Paul was telling Titus here. The context of this verse is about the way we live our lives. Prior to this verse, he had warned about those whose teachings lead to ungodly lifestyles. And following this verse, Paul instructed Titus about how believers should live and interact with each other.
It is easy to distinguish between doctrine (Christian beliefs) and ethics (how we live). And unfortunately, it seems that we often put more emphasis on doctrine than ethics. But the writers of the inspired Scripture focused just as much, if not more, on good ethics as they did on correct belief. As believers in the Lord Jesus, we are called to live godly and holy lives. To be sure, correct doctrine is important. But it is worthless if not reflected in holy living.
If you teach others, it is important that you not be content with just teaching doctrine. Be sure that you also practice and teach the ethics of the Christian life. Ethics that is appropriate to sound doctrine. It can be uncomfortable telling people how they should live. But it is an essential aspect of passing on our faith and raising up the next generation of believers.