The idea of guarding something is defensive in nature, but sometimes the best defense is a good offense. Check out this down-home strategy to guarding your heart.
Some people sell happiness as the end goal of faith. On the other extreme are people who believe Christians should not strive for earthly happiness, but joy focused on the eternal. The Bible supports a more moderate view - Christians can pray for happiness, pursuing heavenly things while finding happiness in the life that has been given them on earth.