“Salvation flows from its deep source in the triune God, who is the fountain of salvation.
This phrase, fountain of salvation, goes back at least to a Latin hymn from the sixth century that praises God as fons salutis Trinitas. As one English translation renders the lines, ‘Blest Trinity, salvation’s spring, may every soul Thy praises sing.’
The sense that the nature of salvation is only understood properly when it is traced back into its principle in the depth of God’s being is evoked by Scripture’s own way of speaking.
The Old Testament bears witness to it in an intensely personal idiom, as for instance in Isaiah 12:2’s confident boast, ‘Behold, God is my salvation; I will trust, and will not be afraid; for the LORD GOD is my strength and my song, and he has become my salvation.’
The connection here between God and salvation is direct: He is it.
When Isaiah goes on to spell out an implication of salvation being in God, that is, that there is exuberant resourcefulness to be drawn from, then he uses our fontal image: ‘With joy you will draw water from the wells of salvation.’ (Isaiah 12:3)
According to Christian teaching, salvation’s source is God, and the manifestation of God as Father, Son, and Holy Spirit in the gospel is what opens up that fountain in its fullness and depth.”
–Fred Sanders, Fountain of Salvation: Trinity and Soteriology (Grand Rapids, MI: Eerdmans, 2021), 14-15, 17.