Unless your life and actions are accompanied by a sense of inner grief you cannot endure the incandescence of stillness. If with this sense of grief you meditate–before they come to pass–on the many terrors that await us prior to and after death you will achieve both patience and humility, the twin foundations of stillness.
Without them your efforts to attain stillness will always be accompanied by apathy and self-conceit. From these will arise a host of distractions and day-dreams, all inducing sluggishness. In their wake comes dissipation, daughter of indolence, making the body sluggish and slack and the intellect benighted and callous. Then Jesus is hidden, concealed by the throng of thoughts and images that crowd the mind (cf. John 5:13).
~St Gregory of Sinai
Prayerful Life 