10 There are many people who refuse to cooperate, who talk about worthless things and lead others into the wrong way—mainly those who insist on circumcision to be saved. 11 These people must be stopped, because they are upsetting whole families by teaching things they should not teach, which they do to get rich by cheating people.12 Even one of their own prophets said, "Cretans are always liars, evil animals, and lazy people who do nothing but eat."13 The words that prophet said are true. So firmly tell those people they are wrong so they may become strong in the faith,14 not accepting Jewish false stories and the commands of people who reject the truth.15 To those who are pure, all things are pure, but to those who are full of sin and do not believe, nothing is pure. Both their minds and their consciences have been ruined.16 They say they know God, but their actions show they do not accept him. They are hateful people, they refuse to obey, and they are useless for doing anything good.
On the whole, this passage pushes us to be active in building up our spirituality and knowledge of the Truth given to us in His word (the Bible). There are a couple very important reasons for this. Firstly, it serves as training for believers to be on the lookout for people who teach wrong doctrines and can potentially lead others astray. This can be anywhere from well-intended teachers who are simply confused and speak opinions without thoroughly checking them against the Bible, to others who have truly evil motives and only pretend to be Christians to get more money, to network, or to attain status/power by being a leader in the church.
The other key reason to continually learn God's truth is that it transforms your mind and world-view. Reading and meditating on His word molds our souls to become filters through which we perceive situations in our lives. A heart that is truly Christ centered will learn to see even the goodness in this world. But an evil and corrupt heart will always find something to taint even the good that they see and hear. Whatever a person chooses to fill their minds and hearts with will change how they act and think.
