5 Believe then that the Son is equal with the Father; but yet that the Son is of the Father; but the Father not of the Son. The Original is with the Father, equality with the Son. For if He be not equal, He is not a true Son. For what are we saying, Brethren? If He is not equal, He is less; if He is less, I ask the nature that needs to be saved, in its misbelief, “how is He born less?” Answer, Does He as being less grow or not? If He grows, then the Father grows old.
But if He will ever be what He was born; if He was born less, He will continue less; with this His loss He will be perfect; born perfect with this loss of the Father's Form, He is never to attain to the Father's Form. Thus do you ungodly assail the Son; thus do you heretics blaspheme the Son. What then says the Catholic faith? The Son is God, of God the Father; God the Father, not God of the Son. But God the Son equal with the Father, Born equal; not Born less, not made equal, but Born equal.
What the Father is, That is He also who was born. Was the Father ever without the Son? God forbid! Take away your “ever,” where there is no time. The Father always, the Son always. The Father without beginning of time, the Son without beginning of time; the Father never before the Son, the Father never without the Son. But yet because the Son is God of God the Father, and the Father God, but not of God the Son; let not the honouring of the Son in the Father displease us. For the honouring of the Son gives honour to the Father, it diminishes not His Own Divinity.
Source: Sermons on Selected Lessons of the New Testament (New Advent)