The letter to Timothy is filled with descriptions of 'correct' behaviour. Some of it might not fit in with the way we think today. Wives are not necessarily submissive to their husbands, and we do not allow slavery.
Some of it sounds a bit too much, but there is definitely a point to it all. We worship and glorify God with our everyday behaviour and the way that we treat one another. When we act according to these teachings, we give a powerful witness to the rest of the world. No one will ever be able to criticize our community because of our bad example. We should be aware of the impression we make on others by our words and deeds.
The parable uses the example of slaves, and we would not use it today. But again, it has a point. The slave would not expect to be rewarded or thanked for doing his job. Likewise, we should not expect praise or rewards for what we are supposed to do, which is doing the will of God with compassion, humility, and justice. It is simply who and what we are.
Lord, may my manner of life always be a good example to others.