Today, reading Arnobius's screed against pagan religion, he offers an interesting statement about God's gender: he claims Christians refer to God in the masculine manner out of custom or habit of speech - not as a reflection of God's nature:
And yet, that no thoughtless person may raise a false accusation against us, as though we believed God whom we worship to be male - for this reason, that is, that when we speak of Him we use a masculine word, - let him understand that it is not the sex which is expressed, but His name, and its meaning according to custom, and the way in which we are in the habit of using words [alt. with familiarity of speech]. For the deity is not male, but His name is of the masculine gender. (Arnobius, adversus Gentes 3.8)