The Bible says a lot about thinking.  We're told to take our thoughts captive to the obedience of Christ; think about things above, be transformed by the renewing of our minds, and to prepare our minds for action.  One passage that I have memorized and have found extremely helpful is Phillipians 4:8:  "Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things."  Here Paul tells us the things we should be thinking about.

I know it's true for me, and I suspect that it's true for most people, that most if not all of our sins, worries, doubts, unforgiveness and frustrations start in our thought life.  Also, I'm learning, that godly thinking takes discipline.  This means it will be hard and unnatural at first.  Perhaps that's why Paul also uses such a forceful verbal when he tells us to 'take every  thought captive'... taking captives is no easy task.  Taking our anxious,sinful, hostile or self-centered thoughts captive is no walk in the park either.

Before going further, I need to say that anxiety disorders are real, medical conditions.  I was diagnosed with anxiety disorder, and the doctor who diagnosed this condition was a conservative Christian.  Faith and medicine, like faith and science in general, are not opponents.  However, just like people with a natural tendency toward heart disease needs to regulate their diet, so I have had to learn to take thoughts captive.

In the Sermon on the Mount, Jesus spoke of not worrying about food or clothing, using God's care for birds and wildflowers as metaphors.  But He doesn't leave his audience with a simple, "Don't worry about it."  This is His lead in to His famous statement, "Seek first the kingdom of God, and His righteousness, and all these things will be given unto you."  Simply put, His message here isn't 'don't worry', but 'replace worries with thoughts of God, what He's doing , and how to be right with Him."  Discipline.

As mentioned earlier, Paul tells us very specific things to discipline our minds by focusing upon:

Whatever is true: like middle ages Katniss Everdeen in the Hunger Games, we are to remind ourselves of what is true to help us believe the harder truths in life.  For example, it is truth that God is good to those who call Him Father.  Therefore, a struggle is not God 'messing with me', punishing me,forgetting or not caring.about me. Yes, it could be His correction - different from punishment, because punishment has an element of implied revenge, whereas correction is intended to help the recipient mature and grow.  It's so easy for me, natural really, to believe untruths, connect wrong dots, draw wrong conclusions.  It's so much harder to stand on truth even when it's hard to believe.  Discipline.

Whatever is honorable.  This one is closely linked to forgiveness.  Forgiveness is often misunderstood.  Forgetting is not a part of it.  An abused spouse is never expected to forget what she's been through, which could perhaps lead to her returening to the same relationship and the same patterns again and again.  Forgiving is more about thinking honorably; being the bigger person, as they say.  Thinking honorably means, in part, desiring the repentance and redemption of the other person; it means not allowing a person's past behaior toward me keep hurting me and being a major focus of my thought life.  Discipline.

Whatever is just:  It is easy to focus on only God's love and blessings, but He is also perfectly just.  I must consider the consequences - physical, spiritual, emotional and social - of choices I make. If forgiving involves thinking about past events, justice requires considering the future, both near and distant, then rethinking how to behave and speak.  Discipline.

Whatever is pure.  This one's pretty straight forward, and perhaps the most difficult of all.  Jesus taught, also in the Sermon on the Mount, when we look at someone lustfully we have already committed adultery in our hearts. This is ridiculously counter-cultural, yet it is truth.  The primary point Jesus was making with this statement is not how hard we must work to make ourselves morally good, but rather how desperately we need redemption.  Even if we can control our outward actions (like the Pharisees?) it is only with the power of the Holy Spirit that our inner man can be controlled.  If I am to take thoughts captive to the obedience of Christ, it can only be done by and through Him.  Here, I think, Paul's theme may take a subtle turn away from discipline to a different theme: Grace.

Whatever is lovely.  This is a tough one, because, from my research, the original Greek word used here is very obscure and used only once in Scripture.  One commentary defined it like this: "The basic meaning of the word is ‘that which calls forth love, love-inspiring,’ and here it has the passive sense of ‘lovely, pleasing, agreeable, amiable’” (O’Brien, P. T., The Epistle to the Philippians, Eerdmans, 1991, p. 505). If this is accurate, then we are to think of the things that inspire love. Does this mean things that will inspire us to love even the 'unloveable': our enemies, criminal offenders, addicts?  If so there is only one blessing from God that, when I think of it, inspires that unconditional love.  Grace.

Whatever is gracious.  If 'lovely' was a hard word to understand in this passage, this one is crystal clear.  Think about the things that are gracious.  Think about God's grace.

If there is any excellence:  Here Paul takes a grammatic turn.  Instead of listing out things to focus our thoughts on - "Whatever is..." he now begins to write as if his last two points are dependent on circumstances: "IF there is any excellence" implies there might NOT be any excellence, at least at a given point in time.  Not being a theologian nor a Greek scholar, I read this at face value.  When my thoughts are racing, desairing, anxious, or full of doubt, I try to reflect on my day and something that was excellent, or something that excelled: a sunset, a conversation, a creative inspiration.  

If there is anything worthy of praise:  It seems here Paul uses a literary device common in Jewish writings, especially in the Psalms, and that is parallelism.  In other words, this is a restatement of his previous statement.  The most excellent things are the things from God, and therefore, are worthy of praise.  It strikes me as ironis, really, that Paul says "IF there is anything worthy of praise".  Of course there are always things worthy of praising God for:

the truth of His Word and promises,

the honor He bestows on those who serve Him, even unto death,

His ultimate perfect justice,

His moral purity,

His example as a Lover,

And His saving and sanctifying grace 

Think about these things.