Is the phrase, "Heaven is the presence of God, but Hell is the absence of God" an orthodox viewpoint? Is the phrase, "Heaven is the presence of God, but Hell is the absence of God" an orthodox viewpoint?  

By orthodox I mean orthodox with a lower case o, not an upper case O, as in Orthodox. 

I used this idea when responding to another question regarding exclusion from heaven here:
Will good, God-fearing people who don&#39;t believe in Jesus&#39; divinity be excluded from Heaven?. 

More to the point, does this phrase describe the primary characteristics of both places, and what verses support/refute this idea?
Depends on what you mean by "orthodox", I guess.

According to the Eastern Orthodox, the answer would be "no".


  Origen, and all rationalists who are like him, was not able to
  understand that the acceptance or the rejection of God's grace depends
  entirely on the rational creatures; that God, like the sun, never
  stops shining on good or wicked alike; that rational creatures are,
  however, entirely free to accept or reject this grace and love; and
  that God in His genuine love does not force His creatures to accept
  Him, but respects absolutely their free decision.  He does not
  withdraw His grace and love, but the attitude of the logical creatures
  toward this unceasing grace and love is the difference between
  paradise and hell. Those who love God are happy with Him, those who
  hate Him are extremely miserable by being obliged to live in His
  presence, and there is no place where one can escape the loving
  omnipresence of God.


http://www.orthodoxpress.org/parish/river_of_fire.htm