As a teacher of the contemplative mind, Philippians is probably my favorite of Paul's letters, because it describes how we need to work with the mind. Paul writes his letter to the Philippians during one of his many imprisonments. He even speaks of being "in chains," and yet ironically this is the most positive and joy-filled of all of his letters. The very fact that he can be so happy during such hardship tells us he had learned what to do with the rebellious and angry mind. We have had no training in that for centuries, and we see the sad results on the streets and in the Congress of America.
In a most succinct and perfect summary, Paul says that you should "Pray with gratitude, and the peace of God which is beyond all knowledge, will guard your hearts and your minds in Christ Jesus" (Philippians 4:7). First, you must begin with the positive, with gratitude (which might take your whole prayer time). Second, you need to pray however long it takes you to get to a place beyond agitation, or to find "peace" (whether five minutes or five hours or five days). Third, note that he says this is a place beyond "knowledge," beyond processing information or ideas. Fourthly, you must learn how to stand guard, which is what many call "creating the inner witness" or the witnessing presence that calmly watches your flow of thoughts (mind) and feelings (heart). Finally, you must know what the goal is: your egoic thoughts can actually be replaced with living inside the very mind of Christ (en Cristo). This is not self-generated knowing, but knowing by participation--consciousness itself (con-scire, to know with). This is major surgery, and Paul says it all in one condensed verse!
Paul then goes on to suggest that we fill our minds "with everything that is true, everything that is noble, everything that is good, everything that we love and honor, everything that can be thought virtuous or worthy of praise" (Philippians 4:8). Norman Vincent Peal calls this "the power of positive thinking." I call it "replacement therapy." If you don't choose love and compassion, the human mind naturally goes in the other direction, and a vast majority of people live their later years trapped in a sense of victimhood, entitlement, and bitterness.
We are not free until we are free from our own compulsiveness, our own resentments, our own complaining, and our own obsessive patterns of thinking. We have to catch these patterns early in their development and nip them in the bud. And where's the bud? It's in the mind. That's the primary place where we sin, as Jesus himself says (Matthew 5:21-48). Any later behaviors are just a response to the way our mind works. We can't walk around all day writing negative, hateful commentaries about other people in our mind, or we will become hate itself!