If any man attempt to speak of God, let him first describe the bounds of the earth. You dwell on the earth, and the limit of this earth which is your dwelling you know not: how then shall you be able to form a worthy thought of its Creator? You behold the stars, but their Maker you behold not: count these which are visible, and then describe Him who is invisible, Who tells the number of the stars, and calls them all by their names. Violent rains lately came pouring down upon us, and nearly destroyed us: number the drops in this city alone: nay, I say not in the city, but number the drops on your own house for one single hour, if you can, but you can not. Learn then your own weakness; learn from this instance the mightiness of God: for He has numbered the drops of rain, which have been poured down on all the earth, not only now but in all time. The sun is a work of God, which, great though it be, is but a spot in comparison with the whole heaven; first gaze steadfastly upon the sun, and then curiously scan the Lord of the sun. Seek not the things that are too deep for you, neither search out the things that are above your strength: what is commanded you, think thereupon.
But some one will say, If the Divine substance is incomprehensible, why then do you discourse of these things? So then, because I cannot drink up all the river, am I not even to take in moderation what is expedient for me? Because with eyes so constituted as mine I cannot take in all the sun, am I not even to look upon him enough to satisfy my wants? Or again, because I have entered into a great garden, and cannot eat all the supply of fruits, would you have me go away altogether hungry? I praise and glorify Him that made us; for it is a divine command which says, Let every breath praise the Lord. I am attempting now to glorify the Lord, but not to describe Him, knowing nevertheless that I shall fall short of glorifying Him worthily, yet deeming it a work of piety even to attempt it at all. For the Lord Jesus encourages my weakness, by saying, No man has seen God at any time.
Cyril of Jerusalem, Catechetical Lecture 10, sections 4 & 5. Today is the Feast of St. Cyril of Jerusalem, Doctor of the Church; his catechetical instructions are probably the best examples of catechesis prior to St. Peter Canisius's, and still hold up well for their clarity, insight, and profundity. St. Cyril was bishop of Jerusalem; we don't know a huge amount about his life, but we do know that he attempted after the Council of Nicaea to take a conciliatory approach, affirming the basic Nicene doctrine but avoiding the controversial term, homoousios: pure Arianism was rejected outright, and Cyril's theology is always consistent with Nicene theology, but he seems to have been in practice a definite supporter of semi-Arian compromises. Many people in the post-Nicene period seriously attempted this approach, but not all with success, and St. Cyril was one of the unfortunate ones in this respect. The Council of Nicaea had given Jerusalem an honorary place with the greatest Sees in Christendom -- Rome, Constantinople, Alexandria, and Antioch. But in practice the Bishop of Jerusalem was beholden to the Bishop of Caesarea, a much more important city in the Empire. The Bishop of Caesarea, Acacius, was strongly Arian and seems not to have been pleased by the honor given Jerusalem by Nicaea; any relationship between Cyril and Acacius deteriorated seriously. Acacius called a council that deposed Cyril as bishop, on the charge of selling church property. It isn't clear from what we know whether this charge was contrived or whether Cyril was actually doing it, with the purpose of using the money to help the poor. There is some evidence that the latter was true: that he was selling church objects to help relieve Jerusalem during a famine. But the real motivation seems to have been that Cyril was teaching the Nicene doctrine in his catechetical lectures and homilies. In any case, Cyril was forced into exile in Tarsus. As often happened at the time, a more moderate council, not quite pro-Nicene but semi-Arian and therefore critical of the stronger Acacian position, met at some point later (Cyril attended) and deposed Acacius, returning Cyril to Jerusalem; by pulling strings with the Emperor the Acacians got this reversed, and Cyril went back into exile. When the Emperor died and Julian (the very same Julian known as the Apostate) came to power, Cyril was able to return. He would later by exiled again by the pro-Arian Emperor Valens, but was able to return when Gratian became Emperor. He eventually voted for the homoousion clause at the First Council of Constantinople, thus finally breaking away from the semi-Arian compromise.