10. The Father only is the true
God, as it is said, John 17:3, “That they might know thee, the only true God” Therefore
the Son is not the true God. Ans. 1. According to the sixth general rule, there
is not here an opposition of the Father, Son and Holy Ghost; but of the true
God, with idols and creatures. Therefore the particle only does not exclude the
Son and Holy Ghost from Deity, but only those who whom he is opposed. 2. There
is a fallacy in dividing clauses of mutual coherence and necessary connection;
for It follows in the passage above referred to, “and Jesus Christ whom thou
hast sent.” Therefore eternal life also consists in this, that Jesus Christ,
sent of the Father, might likewise be known to be the true God, as it is said, “This
is the true God and eternal life.” 3. There is also a fallacy in referring the
exclusive particle only to the subject three, to which it does not belong; but
to the predicate the true God, which the article in the Greek plainly shows;
for the sense is, that they might know thee, the Father, to be that God, who
only is the true God. (The Commentary of Zacharias Ursinus: On the
Heidelberg Catechism—The Protestant Christian Doctrines, Dating to 1563 [trans.
G. W. Williard; Pantianos Classics, 1888], 217)