I observe and believe that one of the reasons the modern Christian church and Christianity has so widely become weak, ineffective, shallow, worldly etc., is because of the lack of Christian meditation being taught, promoted and practiced among so-called believers.
Of course, Eastern meditation is something altogether different and not to be practiced by believers. Biblical meditation, however, is related to and as critical as prayer in producing real Christian spiritual experience and growth, protection. The Bible, God's Word, speaks often of meditation.
"Isaac went out to meditate in the field toward evening --" (Gen. 24:63)
"This book of the law shall not depart from your mouth, but you shall
meditate on it day and night, so that you may be careful to do according
to all that is written in it; for then you will make your way
prosperous, and then you will have success." (Though Joshua was busy supervising the conquest of Canaan, the Lord commanded Him to meditate on the book of the law continually, Josh 1:8)
"When I think of You as I lie on my bed, I meditate on You during the night watches--" (David speak of meditating on the Lord in the night watches, Psalm 63:6)
"My eyes anticipate the night watches, That I may meditate on Your word." (Psalm 119:148)
"Tremble, and do not sin; Meditate in your heart upon your bed, and be still." (Psalm 4:4; also see Pss. 77:10-12; 104:34; 119:116, 48,59,78,97-99)
The Puritans--believers who are not known for shallow, over-emotional, imaginative spiritual frivolity or New Age-like doctrinal error . . . spoke and wrote much on the importance and even critical necessity of Christian meditation as being a regular, critical, habitual part of a believer's spiritual practices.
Thomas Watson (1620-1686) described meditation as "a holy exercise of the mind whereby we bring the truths of God to remembrance and do seriously ponder upon them and apply them to ourselves."
Christian meditation should exercise both mind and heart, intellect and affections.
"A true meditation is when a man does so meditate of Christ as to get his heart inflamed with the love of Christ; so meditate of the Truths of God as to be transformed into them; and so mediate of sin as to get his heart to hate sin." (Edmund Calamy, 1600-1666)
If you want to grow in Christian graces and to become increasingly impervious to the vicissitudes of worldly trials, attacks, temptations etc., you should learn to make (Christian) meditation a daily duty, along with prayer and the reading of the Word. What spiritual blessings ensue when this is done! What sweetness develops all around the contemplation, study, mulling and practice of Biblical truths and practices! There is nothing in the world like it! The further you go in developing such practice, the more the world and all its threats, harrowings, entanglements upon your mind, heart and soul, begin to pale and become brittle, weak and fall away . . . and the more you start gaining a powerful hunger and thirst for righteousness and the things of God. Such divine relations become so fulfilling that all other temporal comforts and appetites vastly loose their savor in comparison.
Powerful, serious and effective meditation should be daily, deliberate and set for a regular time. It is, "when a person sets apart . . . some time, and goes into a private closet, or a private walk, and there does solemnly and deliberately meditate of the things of Heaven . . . [It] is a reflecting act of the soul, whereby the soul is carried back to itself, and considers all the things that it knows" about a particular Biblical subject, including its "causes, fruits and properties." (Calamy)
Among the physical preparations a wise steward ought be making at this time, installing this Christian practice is crucial . . . in order to hear correctly and regularly the promptings and corrections of the Spirit . . . during calamitous times, to stay spiritually strong, safe, directed. . . .