Paul was giving instruction to Timothy, one of his close associates. Timothy was with Paul during many of his missionary journeys, where Timothy no doubt encouraged Paul. Now, Paul was writing to encourage Timothy.
In one verse, Paul draws a sharp contrast between two different lifestyles. The first follows the "irreverent and silly myths" invented by the sinful inhabitants of the world we live in. The other is a lifestyle of godliness. Paul discouraged Timothy from the former and encouraged the latter.
Note here that Paul does not tell us to let our pastor train us in godliness. He also does not delegate this to the deacons. Rather, Paul encourages Timothy to train himself in godliness. It is our responsibility to search the Scriptures. It is not the responsibility of the pastor to spoon-feed us the Gospel. It is our responsibility to seek out the truth of God's word.