When Should we Pray?

Is prayer important? What about when everything is going well? We need to pray that God would impress on us our total inadequacy every minute of every day, not just when we're in a trial.
It is interesting that at least one of our founding fathers verbalized this before a pretty important group of men and preceding a pretty important undertaking.

Benjamin Franklin: Speech in Convention for forming a Constitution for the United States, 1787.
"In the beginning of the contest with Britain, when we were sensible of danger, we had daily prayers in this room for the Divine protection. Our prayers, sir, were heard, and they were graciously answered. All of us who were engaged in the struggle must have observed frequent instances of a superintending Providence in our favor. To that kind Providence we owe this happy opportunity of consulting in peace on the means of establishing our future national felicity. And have we now forgotten this powerful Friend? or do we imagine we no longer need his assistance? I have lived for a long time 81 years; and the longer I live the more convincing proofs I see of this truth, that God governs in the affairs of man. And if a sparrow cannot fall to the ground without his notice, is it probable that an empire can rise without his aid? We have been assured, sir, in the sacred writings, that "Except the Lord build the house, they labor in vain that build it." I firmly believe this; and I also believe that without his concurring aid we shall proceed in this political building no better than the builders of Babel: we shall be divided by our little, partial, local interests; our prospects will be confounded; and we ourselves shall become a reproach and a byword down to future ages. And what is worse, mankind may hereafter, from this unfortunate instance, despair of establishing government by human wisdom, and leave it to chance, war, or conquest. I therefore beg leave to move that henceforth prayers, imploring the assistance of Heaven and its blessing on our deliberations, be held in this assembly every morning before we proceed to business; and that one or more of the clergy of this city be requested to officiate in that service".