Plato, Laws 717a

ἄνδρʼ ἀγαθὸν οὔτε θεὸν ἔστιν ποτὲ τό γε ὀρθὸν δέχεσθαι· μάτην οὖν περὶ θεοὺς ὁ πολύς ἐστι πόνος τοῖς ἀνοσίοις, τοῖσιν δὲ ὁσίοις ἐγκαιρότατος ἅπασιν. σκοπὸς μὲν οὖν ἡμῖν οὗτος οὗ δεῖ στοχάζεσθαι· βέλη δὲ αὐτοῦ καὶ οἷον ἡ τοῖς βέλεσιν ἔφεσις τὰ ποῖʼ ἂν λεγόμενα ὀρθότατα φέροιτʼ ἄν; πρῶτον μέν, φαμέν, τιμὰς τὰς μετʼ Ὀλυμπίους τε καὶ τοὺς τὴν πόλιν ἔχοντας θεοὺς τοῖς χθονίοις ἄν τις θεοῖς ἄρτια καὶ δεύτερα καὶ ἀριστερὰ νέμων ὀρθότατα τοῦ τῆς

Therefore all the great labor that impious men spend upon the gods is in vain, but that of the pious is most profitable to them all. Here, then, is the mark at which we must aim; but as to shafts we should shoot, and (so to speak) the flight of them,—what kind of shafts, think you, would fly most straight to the mark? First of all, we say, if—after the honors paid to the Olympians and the gods who keep the State—we should assign the Even and the Left as their honors to the gods of the under-world, we would be aiming most straight at the mark of piety—