The question Edwards spent his life on is how to tell genuine religion from its imitations, and his answer, set out in the Religious Affections of 1746, is deliberately unhelpful to both parties in the revival quarrel. Intensity proves nothing: trembling, weeping, visions, sudden texts coming to mind, even great changes in behaviour, can all occur without grace. Nor does their absence disprove anything. The mark he settles on is a change of taste. A person given grace perceives the beauty of holiness directly, the way one perceives sweetness rather than being told about it, and comes to love God for what God is rather than for what God gives.
That aesthetic centre runs through everything he wrote. Being itself, in his metaphysics, consents to being, and beauty is that consent; virtue is love to being in general; and the created world is a communication of God's own fullness rather than a stage for a transaction. It sits oddly beside his reputation, and it is the reason philosophers still read him.
He was a strict Calvinist and argued the case at length in Freedom of the Will of 1754, which distinguishes natural from moral inability and remains the standard statement of the position in English. He also, like most of the New England clergy of his class, owned enslaved people, which is part of the record and is stated here as such. He became president of the college at Princeton in 1758 and died within weeks, of a smallpox inoculation he had taken to encourage the practice.