St. Augustine In love my God

But what do I love, when I love Thee?

not beauty of bodies, nor the fair harmony of time, nor the brightness of the light, so gladsome to our eyes, nor sweet melodies of varied songs, nor the fragrant smell of flowers, and ointments, and spices, not manna and honey, not limbs acceptable to embracements of flesh. None of these I love, when I love my God; and yet I love a kind of light, and melody, and fragrance, and meat, and embracement when I love my God, the light, melody, fragrance, meat, embracement of my inner man: where there shineth unto my soul what space cannot contain, and there soundeth what time beareth not away, and there smelleth what breathing disperseth not, and there tasteth what eating diminisheth not, and there clingeth what satiety divorceth not.This is it which I love when I love my God. 

Confessions of St. Augustine

Saint Paul Hymn to Love

I speak in the tongues of men and of angels, but have not love, I am a noisy gong or a clanging cymbal. And if I have prophetic powers, and understand all mysteries and all knowledge, and if I have all faith, so as to remove mountains, but have not love, I am nothing. If I give away all I have, and if I deliver my body to be burned, but have not love, I gain nothing.Love is patient and kind; love is not jealous or boastful; it is not arrogant or rude. Love does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrong, but rejoices in the right. Love bears all things, believes all things, hopes all things, endures all things.Love never ends; as for prophecies, they will pass away; as for tongues, they will cease; as for knowledge, it will pass away. For our knowledge is imperfect and our prophecy is imperfect; but when the perfect comes, the imperfect will pass away. When I was a child, I spoke like a child, I thought like a child, I reasoned like a child; when I became a man, I gave up childish ways. For now we see in a mirror dimly, but then face to face. Now I know in part; then I shall understand fully, even as I have been fully understood. So faith, hope, love abide, these three; but the greatest of these is love. (I Corinthians 13) 
Saint Paul’s Hymn to Love

Read more: One God

Empedocles

(Wiki)
'For before now I have been at some time boy and girl, bush, bird, and a mute fish in the sea' (fr. B 117)

Empedocles (encyclopedia of philosophy)

Plotinus

THE SIX ENNEADS, by Plotinus

THE SIXTH ENNEAD: SEVENTH TRACTATE

HOW THE MULTIPLICITY OF THE IDEAL-FORMS CAME INTO BEING:
AND UPON THE GOOD.

(recomended for those who want to understand what God it is or better it is not. Plotinus is  neoplatonist and he is difficult to read but sure is understandable for those who have philosophy background)