In 1776, our country's founding fathers signed a document at Independence Hall called the Declaration of Independence. I think it's an amazing document for a number of reasons, but chiefly because it says something that is different from any other foundational document for any other country on the planet.

You probably know at least a few of its famous words:

"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."

The last phrase in this sentence particularly catches my attention: "the pursuit of Happiness." It was the intent of our founding fathers that we, as Americans, be happy people.

A lot of time has passed since that document was signed. Could we be described as a happy people today? I would have to say "no." Americans, as a whole, enjoy a higher standard of living than anyone else in the world. Yet more Americans go to psychologists and psychiatrists than any other people on the planet.

So what is the problem? I believe that we could boil it down to this: we are pursuing happiness, but we are going about it in the wrong way. For most people, their happiness depends entirely on good things happening in their lives. When things are going well, they are happy. When things are not going well, they are unhappy.

This can cause us to become caught in an endless cycle, because no matter how much we accumulate or how much we accomplish, we always will feel as though there is something more. Our clothes aren't fashionable enough. Our cars aren't fast enough. Our houses aren't elaborate enough. Our jobs aren't rewarding enough. Our relationships aren't romantic enough or fulfilling enough.

As Solomon said, "The eye is not satisfied with seeing, nor the ear filled with hearing" (Ecclesiastes 1:8 NKJV). Life can become a never-ending pursuit of something just beyond our grasp.

The Book of Philippians talks about something better than happiness, or at least the world's version of it. It's called joy. In Philippians' four chapters, the words joy, rejoicing, or gladness appear at least 19 times. This joy to which Philippians refers was not something available to first-century believers alone. It is available to 21st-century believers as well.

We find an important word throughout Philippians that shows us the way to experience joy. That word is: mind. It appears 10 times in Philippians, while the word think occurs five times. Add to this the number of times the word remember turns up, and you have a total of 16 references to the mind. So, we see that the secret of Christian joy is found in the way a believer thinks, in his or her outlook or attitude.

Throughout his letter to the Philippians, the apostle Paul exemplifies these principles. First, he demonstrates the single mind. He said in chapter 1, "For to me, to live is Christ" (verse 21). Then in chapter 3, he said, "but one thing I do" (verse 13). In other words, Paul understood that the main thing was to keep the main thing the main thing. First and foremost in his life was Jesus Christ.

Second, Paul had the mind of Christ. He said, "Let this mind be in you which was also in Christ Jesus" (Philippians 2:5). That is the mind of a person who puts the needs of others above his own. It stands in sharp contrast to our self-centered attitudes of today.

Third, Paul had the mind of spiritual growth and progression. Not one to think that he had reached a state of spiritual perfection, he said, "Not that I have already attained, or am already perfected, but I press on..." (Philippians 3:12). He refused to live in the past. He recognized that he still had a long way to go.

Finally, Paul had a rejoicing mind. In chapter 4, he said, "Rejoice in the Lord always. Again I will say, rejoice" (verse 4). Paul was an unlikely person to be talking about rejoicing, because he was in prison when he wrote this epistle. Yet the theme of his letter was joy.

Today, God promises believers the same kind of joy — a joy that will be with them no matter what they are going through. Paul's joy was not coming from what he had, but from whom he knew: Jesus Christ.