Never shall God be hidden, never shall God be wanting. Always shall He be understood, always be heard, nay even seen, in whatsoever way He shall wish. God has for His witnesses this whole being of ours, and this universe wherein we dwell. He is thus, because not unknown, proved to be both God and the only One, although another still tries hard to make out his claim.
Tertullian
The Five Books Against Marcion, Book I
Chapter X