St. Symeon the New Theologian: Lamentation comes upon me; my heart is consumed, and I pine away for your sake...

Lamentation comes upon me; my heart is consumed, and I pine away for your sake, when I remember that we have such a generous Master, so full of loving-kindness to us men that in return for simple faith in Him He grants us such gifts as surpass our understanding, our hearing, our thinking, such as "the heart of man has not conceived" (1 Cor. 2:9). 

But we are like brute beasts and prefer nothing but the earth and the things that, through His great mercy, it produces to satisfy the needs of bodies! These are for our moderate sustenance, so that our souls may make the journey to the things that are above without hindrance, as they are likewise fed with the rational food of the Spirit according to the extent that they have been cleansed and ascend.

St. Symeon the New Theologian