Caelius has a nice one up today at Monastery of the Remarkable English Martyrs. I especially like the thing about surprise:
I found this observation from Fr. Charles OFM Cap. to pair well with the passage from William James quoted by A Thinking Reed
A merely human religiosity can see prayer as an addressing of ourselves to a deity somewhere up in the sky, either literally or in some rarefied sky more palatable to persons imbued with modern science. [...] From the call of Abraham to the Resurrection appearances, Christian faith speaks of a God who arrives, who is adventitious. He is not a supreme being who must be pulled down from the sky or a cthonic power that must be conjured up from the netherworld. Rather, he is a Presence discovered, sometimes as a surprise, as with Abraham and the three men, or simply recognized precisely when he calls us by name, as with the Risen Lord and Mary Magdalene. Prayer and adoration, then, as the postures that make us disciples of Jesus Christ, are acts of hospitality, of graciously receiving the Presence of God as he arrives in the particular circumstances of our days.