3 Yet it cannot be denied that Christ was Christ. It cannot be that He was incognisable to mankind. The books of the prophets have set their seal upon Him: the fullness of the times, which waxes daily, witnesses of Him: by the working of wonders the tombs of Apostles and Martyrs proclaim Him: the power of His name reveals Him: the unclean spirits confess Him, and the devils howling in their torment call aloud His name. In all we see the dispensation of His power. But our faith must preach Him as He is, namely, one Lord not in name but in confession, in one faith of one baptism: for on our faith in one Lord Christ depends our confession of one God the Father.
Source: On the Trinity (New Advent)