You also need to make offerings, sacrifices, and give first fruits according to your country's customs. Do this purely and carefully — not carelessly or sloppily. Don't be cheap about it, but don't go overboard either.
But it also becomes incumbent on everyone to offer libations and sacrifices and first fruits, according to the customs of his country, purely, and not heedlessly nor negligently; not avariciously, nor yet extravagantly.
If you think anything else is truly good or bad, you'll inevitably blame others when things don't go your way. When you don't get what you want or when bad things happen to you, you'll point fingers at whoever you think is responsible. Every living thing naturally runs from what seems harmful and chases what seems beneficial. So it's impossible for someone who thinks they're being hurt to feel good about the person hurting them. It's also impossible to feel good about the harm itself. This is why a father gets cursed by his son when he doesn't give him things the son thinks are good. This is what made Polynices and Eteocles enemies — they both thought having power was good. This is why farmers curse the gods, and so do sailors, merchants, and people who lose their spouse or children. We direct our devotion toward whatever we think serves our interests. So if you want to be truly pious, you must first learn to want and avoid the right things.
For if you suppose any other things to be either good or evil, it is inevitable that, when you are disappointed of what you wish or incur what you would avoid, you should reproach and blame their authors. For every creature is naturally formed to flee and abhor things that appear hurtful and that which causes them; and to pursue and admire those which appear beneficial and that which causes them. It is impracticable, then, that one who supposes himself to be hurt should rejoice in the person who, as he thinks, hurts him, just as it is impossible to rejoice in the hurt itself. Hence, also, a father is reviled by his son when he does not impart the things which seem to be good; and this made Polynices and Eteocles mutually enemies—that empire seemed good to both. On this account the husbandman reviles the gods; [and so do] the sailor, the merchant, or those who have lost wife or child. For where our interest is, there, too, is piety directed. So that whoever is careful to regulate his desires and aversions as he ought is thus made careful of piety likewise.