Proverbs 4:23 (NLT)
23 Guard your heart above all else, for it determines the course of your life.

King Solomon shares this piece of wisdom that we must maintain a holy jealousy of ourselves and ensure that all areas of our soul are guarded. We are to not let our hearts hurt others, nor are we to let others hurt our heart. Our hearts should remain free from sin and not disturbed by the trouble that comes into our lives. We are to have a good conscience; keeping good thoughts and not bad ones. We must keep our hearts with more diligence than any other part of us, because all issues of life are directed by the heart. Our lives will follow the path of our heart making us comfortable or uncomfortable, rejoiceful or distraught.

We owe it to our husband or wife, our fellow workers, our children, our friends, indeed to everyone who comes into our lives, to be as happy as we can be. This does not mean acting unreal, and it certainly does not mean refraining from honest and intimate expressions of our feelings to those closest to us. But it does mean that we owe it to others to work on our happiness.... I once asked a deeply religious man if he considered himself a truly pious person. He responded that while he aspired to be one, he felt that he fell short in two areas. One of those areas, he said, was his not being a happy enough person to be considered truly pious. His point was that unhappy religious people reflect poorly on their religion and their Creator. He was right; in fact, unhappy religious people pose a real challenge to faith. If their faith is so impressive, why aren't these devoted adherents happy? There are only two possible reasons: either they are not practicing their faith correctly, or they are practicing their faith correctly and the religion itself is not conducive to happiness. Most outsiders assumer the latter reason. Unhappy religious people should therefore think about how important being happy is -- if not for themselves, then for the sake of their religion. Unhappy, let alone angry, religious people provide more persuasive arguments for atheism and secularism than do all the arguments of atheists. [Dennis Prager, talk show host, author, columnist , Happiness Is a Serious Problem (Regan Books, 1998), p.4]