Calvin continues to argue that the Son of God is Yahweh by drawing out the implications of various biblical texts. For example: the New Testament contains instances of prayer directed to Christ; therefore Christ must be Yahweh.
Otherwise, not only would Stephen have violated the lawful form of prayer when he prayed to Christ (Acts 7.59), but the whole church, too, would be guilty of the same impiety. The God of Israel, whom the pretender who authored the document1 wishes to be the Father alone, considers calling upon his name of more moment than all sacrifices, and claims this honor for himself as the chief sacrifice (Psalm 50.14). But what of Stephen? He directs his prayer to Christ. According to Luke, moreover, Ananias says that all the pious called upon the name of Christ (Acts 9.14). How will these things be consistent with themselves, namely that Christ is properly called upon in prayer and that he nevertheless is not that God who, through David, demands the sacrifice of praise? Therefore the fiction that Scripture everywhere speaks of the Father and the Son in distinction from one another is overturned, since it often mentions the one and only deity of each under the one name of Yahweh. When the Son is joined to the Father, however, it is no surprise that his proper Person is attributed to each one.2