In all this, and in what has been said above, one should keep a proper order, and one should work on whatever one understands. For what one cannot understand one should give silent thanks, as St Isaac says, but should not presumptuously assume that one has understood it. And St Isaac, borrowing his words from Sirach, also says: “When you find honey, eat moderately, lest by over-indulging you make yourself sick” (Proverbs 25:16). As St Gregory the Theologian says, ‘Uncontrolled contemplation may well push us over the edge, when we seek for what is beyond our strength and are unwilling to say, ‘God knows this; but who am I?’
~St Peter of Damaskos
Prayerful Life 