Is it too bold of us to declare what God was like, or what he was doing, before creation? It requires boldness, to be sure, but only the boldness of the New Testament.
One of the characteristic differences between the Old Testament and the New Testament is that the New Testament is bold to make such statements. Look, for instance, at the way the New Testament takes a step further back with its declaration of salvation: where God declares in the old covenant, “I have chosen you,” the new covenant announces that “he chose us in Christ before the foundation of the world.”
The prophets do not make declarations about what happened “before the foundation of the world,” but the apostles do.
Fred Sanders, The Deep Things of God (Wheaton: Crossway, 2010), 63.