Taylor Marshall has an interesting post on The Christian Origin of Neo-Platonism. It’s worth your time, since you’ll often read that the influence ran the other way — and that patristic theology is just Plato dressed up in the vestments of Nicea. But, as Marshall points out, it was the Christian Ammonius (third century) who taught Plato to Plotinus, and Plotinus who taught him to the anti-Christian Porphyry. By the time Neo-Platonism got to Augustine, it was no longer Neo and was considered a pagan thing.
A recent book, The Mysticism of Saint Augustine by John Peter Kenney, argues that Augustine’s Confessions is an artful apologetic against the pagan Neo-Platonism that Augustine had known and loved. In the culminating scene, Augustine portrays his unlettered mother, Monica, in an intellectual ecstasy — the sort of contemplation that Plotinus had sought all his life, but reached only rarely, with great difficulty, and for fleeting moments. (Did Plotinus himself have a Christian phase in his past? Readers ancient and modern have suspected so, with all his talk of a divine triad. Some graces die hard.)
And as long as you’re on your Neo-Platonist kick, read Andrew Louth’s The Origins of the Christian Mystical Tradition: From Plato to Denys.
But do start your binge with Taylor Marshall.