Whether it is necessary for salvation to believe explicitly in the Trinity?

❌ Objection 1 : It would seem that it was not necessary for salvation to believe explicitly in the Trinity. For the Apostle says (Heb. 11:6): "He that cometh to God must believe that He is, and is a rewarder to them that seek Him." Now one can believe this without believing in the Trinity. Therefore it was not necessary to believe explicitly in the Trinity.

❌ Objection 2 : Further our Lord said (Jn. 17:5,6): "Father, I have manifested Thy name to men," which words Augustine expounds (Tract. cvi) as follows: "Not the name by which Thou art called God, but the name whereby Thou art called My Father," and further on he adds: "In that He made this world, God is known to all nations; in that He is not to be worshipped together with false gods, 'God is known in Judea'; but, in that He is the Father of this Christ, through Whom He takes away the sin of the world, He now makes known to men this name of His, which hitherto they knew not." Therefore before the coming of Christ it was not known that Paternity and Filiation were in the Godhead: and so the Trinity was not believed explicitly.

❌ Objection 3 : Further, that which we are bound to believe explicitly of God is the object of heavenly happiness. Now the object of heavenly happiness is the sovereign good, which can be understood to be in God, without any distinction of Persons. Therefore it was not necessary to believe explicitly in the Trinity.