27 Do you suppose, heretic, that the Lord of glory feared to suffer? Why, when Peter made this error through ignorance, did He not call him 'Satan' and a 'stumbling-block?' Thus was Peter, who deprecated the mystery of the Passion, established in the faith by so sharp a rebuke from the lips of the gentle Christ, Whom not flesh and blood, but the Father in Heaven had revealed to him.
What phantom hope are you chasing when you deny that Christ is God, and attribute to Him fear of suffering? He afraid, Who went forth to meet the armed bands of His captors? Weakness in His body, at Whose approach the pursuers reeled and broke their ranks and fell prone, unable to endure His Majesty as He offered Himself to their chains? What weakness could enthral His body, Whose nature had such power?
Source: On the Trinity (New Advent)