One should meditate because a non-meditative mind is a mind that spins and projects and thereby creates a web of its own sucking the individual into its own mechanisations. The mind that generally is considered a blessing to a human being has turned out to be a big nuisance or a curse. Further, this very mind that each has, has turned out to be an obstacle in achieving religious and spiritual ends that one might want to achieve, draining away the energy instead of replenishing the personality with the needed energy. As the mind obtains right now in the vast majority of people also turns out to be a hindrance in gain of knowledge, which is the culmination of spiritual pursuit.
When we have to employ the mind for spiritual pursuits, there is a need for ‘single-pointedness’ and purity that also includes objectivity. In the process of living our lives we seem to have lost the mind that was single-pointed or one-pointed in our childhood. Meditation can be employed for regaining that frame of mind, apart from the dullness that it has inherited over the years. There are other issues too that have to be handled and meditation could be employed to take care of those issues too.
Meditation is a religious or spiritual practice that could be classified as a mental exercise. Tradition uses meditation primarily as a means to make the mind an effective instrument to guide one in the spiritual or religious path depending upon the evolution of the follower/practitioner/seeker. However, people in the world use meditation for various other purposes too right from making oneself an effective person playing mind games or be an effective person in this competitive world and it is also being widely used as a means to removing negative tendencies and also as a technique for reducing stress in order to resolve stress-related problems. These stress-related problems can manifest at the level of the body or the mind.