The idea is to control a busy mind, which is conditioned to constantly adjusting its focus. We either are juggling more than one line of thought; or our emotions are pushing for us to bring a variety of factors into balance which trouble us; or maybe we just think the way the culture comes at us, fast, varied and noisy.
Set aside ten minutes, even if it is scheduled time usually dedicated to prayer. Get quiet and get your surroundings quieted from the noise of the culture. Decide for yourself what supports your endeavors, but even gentle background music is likely to distract. Think about Jesus. Nothing else. Most folks cannot do this. A solid ten minutes on one topic is harder than anyone might think! Make the thoughts come back again and again to just Jesus. Imagining events that include Jesus or Him actively teaching words like the Beatitudes which we associate with Him are a means of maintaining the focus. While disciplining the mind, be somewhat conscious of the body. Keep your breathing even, steady and relatively deep. If tension in one muscle group grabs the attention of the brain, for example you realize you are frowning, relax those muscles purposely and return to the focus on Jesus.
That's it. No bells and whistles, no deep spiritual insights...at first.
Why bother with this? Two things are being learned by the exercise:
Control of thoughts and a sense of dwelling peacefully in the heart with God.
The benefits over time are many. The control of thinking and focus on Jesus will begin to transfer to everyday life. It is discovered that the sense of peace and relaxation associated with a focus on Jesus is transferable to situations in the day to day challenges which are high pressure and intense. A person can learn experientially (not just academically) through meditation on Jesus that life springs from the heart not the intellect. I have heard this called "Practicing the Presence of Jesus."
Further, as the practice continues one learns to listen to the deep Presence of God within. He is alive and so much more than the printed words we have about Him! The written word is vital, absolutely. It provides the frame or mode for our intellect to experience during the exercise which is intended to develop the heart. Think on the things stated in the scripture which reveal Jesus, but avoid attempting to intellectually divide the Word. Rather, allow the heart to know a deep wonder and worship on His being alone.
Words fail to allow me to fully describe what I have come to know through meditation on Jesus. Nonetheless, I encourage it here. The practice itself is not the end. Adding the discipline just as another thing done to reach God is not the point. Rather meditation stands on the notion that the work of Jesus was finished at the Cross. The power of good over evil was accomplished in the Resurrection. The Presense of the Holy Spirit arrived at Pentecost. Meditation is an acceptance that all this is true and to "rest in Him" strengthens the new creature, birthed in spirit, whom the believer is. Prayer is a dedicated time of supplication and making one's requests made known to the Father. Meditation is learning to rest in the beauty and wonder of the Father, present within us through the Holy Spirit, and is a connection authorized by the sacrifice of the Son. Meditation becomes an act of communion with the awesome God we serve.
I do not contend this is a commandment of the Lord for believers from a doctrinal standpoint. However, if you are feeling distant from God, or some of your experiences within modern church practice are not a strength to your heart or you simply desire to increase your heart's capacity for loving God and your neighbor; this may be a useful tool to stir your heart to a deeper sense of the Father as a loving God caring for your soul. When we are more aware of the depth of God's love, we begin to overflow with love for others.