Christian meditation is often associated with prayer or scripture study. It is rooted in the Bible, which directs its readers to meditate. In Joshua 1:8, God commands his people to meditate on his word day and night to instill obedience. The psalmist says that "his delight is in the law of the Lord, and in his law he meditates day and night" (Psalm 1:2). The Bible mentions meditate or meditation twenty times.
http://en.wikipedia.org/wiki/Christian_meditation

Spiritual formation is the growth and development of the whole person by an intentional focus on one’s (1) spiritual and interior life, (2) interactions with others in ordinary life, and (3) the spiritual practices (prayer, the study of scripture, fasting simplicity, solitude, confession, worship, etc.)
.http://en.wikipedia.org/wiki/Spiritual%20formation

Silence: A silent mind, freed from the onslaught of thoughts and thought patterns, is both a goal and an important step in spiritual development. Inner silence is understood to bring one in contact with the divine or the ultimate reality of this moment. All religious traditions imply the importance of being quiet and still in mind and spirit for transformative and integral spiritual growth to occur.
http://en.wikipedia.org/wiki/Silence

Centering prayer is a popular method of contemplative prayer, placing a strong emphasis on interior silence.Contemplative Prayer: As it is expressed in a modern day movement is mystically (i.e. based on a technique or method) in which one empties the mind of thought through repetition, usually of a word or phrase or focus on the breath. In this case the silence would be an absence of thought, all thought.
http://www.lighthousetrailsresearch.com/

Mysticism is a belief in or the pursuit in the unification with the One or some other principle; the immediate consciousness of God; or the direct experience of religious truth. Mysticism is nearly universal and unites most religions in the quest for divinity. It can also be a sense of mystical knowledge. Dionysius the Areopagite was the first to introduce the concept "unknown knowing" to the Western World. In areas of the occult and psychic it denotes an additional domain of esoteric knowledge and paranormal communication. Even though it is thought that just monks and ascetics can become mystics, mysticism usually touches all people at least once in their lives.
http://www.themystica.com/mystica/articles/m/mysticism.html