Joshua 1:8 This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.
My experience is that the majority of Christians do not know how to meditate. When they look to the purpose of meditation they see an end goal. They then begin to look at scripture as a means to an end. They see meditation as an exercise of will, they imagine how the scriptures work. That is not the purpose of meditation.
2 Corinthians 10:5 Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ;
This is the purpose of meditation. Taking captive every thought in obedience of faith. The approach is different in this way, you must see the Word of God for what it is and not what you want it to be. It is within the human experience to relate the Word of God with what we know and understand. This knowledge base, this referral of studies, teachings, sermons, commentaries and personal experience all fill our brains with thoughts which are in many ways a burden. We fear letting go of any of it.
Meditation is letting go of all that is not God’s Word and allowing the Word itself to speak to you from a place of emptiness, humility, and subjection to the Lord.
Letting go of what we think is not easy. Meditation is not thinking. It is letting go of everything which is not God.