There are times when a person’s body
may remain completely still
while the soul serves God in silent prayer.
In such moments your prayer may be filled
with a burning and awesome love,
though one who sees you
might never guess the depth
of your inner service.
Only those who are already at one with God
may attain this prayer
of inner flame and outer stillness.
Such worship has greater power
than devotion which can be seen by others.
The “shells” of evil which feed upon wayward prayers
cannot reach this silent prayer,
for it is deeply hidden within the self.

from: Your Word is Fire – The Hasidic Masters on Contemplative Prayer 
Tr. Arthur Green and Barry W. Holtz