Christians should be examples of doing what is good, and they should be encouraged to do what is good. No one would argue that, especially if you reflect on the eight references in the book of Titus where “doing what is good” are mentioned. But there are many Christians who know what they are to do, but find it very difficult to actually do it.
In Titus 3:1 Paul writes about being ready to do whatever is good. In other words, we are to be prepared. This is a process. The older generation can share what they have learned from their experience. This helps Christians picture what “doing what is good” looks like in actual experience.
Being pure, for example, means being careful about what you watch. It also means to take care what you listen to. Who you associate with is also important. So is what you think about when you’re all alone? What does integrity look like? Being a person of your word. Being the same when the boss is present or absent. Being willing to sacrifice, if necessary, to stand for what is right.
When older Christians share experiences it is easier to prepare yourself than if you are merely taught theory. But the greatest source of enablement is the power of the gospel of grace. Notice that in Titus 2 and 3 two references regarding doing what is good follow in depth discussions of doctrine. In chapter two the doctrine of the return of Jesus Christ is mentioned, and in chapter 3 the doctrine of Salvation. Being saved by God’s grace and anticipating the Savior’s return are enabling factors in doing what is good.