Christian theology ought to be an exercise in knowing God precisely as the God of salvation. But we have not confessed the God of salvation at all if we have not confessed God’s perfection and self-sufficiency apart from any considerations about salvation.
Calvin famously opens his Institutes with the observation that all true and sound wisdom consists in knowledge of God and knowledge of the self. But “which one precedes and brings forth the other is not easy to discern,” on account of how many bonds hold them together, and the way these two knowledges mutually presuppose each other. There seems to be no proper place to start. Calvin proposes this difficulty to his readers as if it is a puzzle to be solved, but he only does so as a rhetorical strategy to draw us into the circle of the exposition of Christian wisdom. In fact, as his ensuing discussion makes clear, it does not matter which subject is treated first, so long as the two come together in the decisive encounter between God and humanity which alone can give us theological insight into both. He invites us to consider the problem of how these two matters are related to each other just so he can engage our minds simultaneously in the contemplation of them both.
With slight adjustments, we can say that the same complex relationship obtains between the doctrine of the Trinity (as knowledge of God) and the Christian doctrine of salvation (which stands here as knowledge of self). The two arise together from the scriptural testimony, because the Bible consistently speaks of salvation and of God together.