Seneca, Letters to Lucilius
41.1-2 (tr. Richard M. Gummere):
God is near you, he is with you, he is within you. This is what I mean, Lucilius: a holy spirit dwells within us, one who marks our good and bad deeds, and is our guardian. As we treat this spirit, so are we treated by it. Indeed, no man can be good without the help of God. Can one rise superior to fortune unless God helps him to rise? He it is that gives noble and upright counsel. In each good man "a god doth dwell, but what god know we not."
prope est a te deus, tecum est, intus est. ita dico, Lucili: sacer intra nos spiritus sedet, malorum bonorumque nostrorum observator et custos; hic prout a nobis tractatus est, ita nos ipse tractat. bonus vero vir sine deo nemo est: an potest aliquis supra fortunam nisi ab illo adiutus exsurgere? ille dat consilia magnifica et erecta. in unoquoque virorum bonorum '(quis deus incertum est) habitat deus' [Verg. Aen. 8.352].