Frederick Copleston, A History of Philosophy, Volume I: Greece and Rome (Westminster: Newman, 1959) 474.
Porphyry was a Neoplatonist philosopher who lived in the third-fourth centuries C.E. Copleston states the following about Porphyry's stance on faith and works:
[Porphyry] insisted on the importance of works, affirming that God does not prize the wise man's words, but his deeds. The truly pious man is not for ever at prayer and sacrifice, but practises his piety in works: God does not accept a man for his reputation or for the empty formulae he employs, but for a life in accordance with his professions.
Copleston cites Ad Marcellam 17 for this point. For the text, see Porphyry, Letter to his wife Marcella. (You'll need to click on "Page" at the bottom to read the letter.)
To be honest, I'm not sure what Porphyry has in mind when he talks about "works." I'm pretty sure what the Bible means by it, since the both Hebrew Bible and the New Testament emphasize caring for the poor. The deuterocanonical writings in the Catholic Bible stress the importance of giving alms. But I don't see anything about that in Porphyry's letter to Marcella.
Instead, Porphyry emphasizes such things as subduing the passions (i.e., anger, jealousy, desire for pleasure). He says that one can become cleansed through toil, asceticism, poverty, and reflection on the pure God, who does not need us yet is eager to help us. He refers to "justice," but he does not define it in his letter. And, in the final paragraph before the letter breaks off, Porphyry exhorts Marcella to "look on the love of mankind as the foundation of your piety." But love for others (especially the poor) is not an emphasis in this letter.
Maybe Porphyry does discuss it in other writings, but I won't be combing through them for the sake of this post. But I can pursue such a project in the future, if I become so motivated.
Porphyry's emphases in his letter to Marcella overlap with the Bible, which talks about purification through trials, a God who's willing to help us, and reflection on the pure God. But the Bible is about more than us thinking about our own spiritual progress. It exhorts us to help the needy as well.
What this means in day-to-day life can be complicated. Do I help every beggar on the street who asks me for money? How do I know he'll spend it on food? Then there are times when I perhaps can buy the beggar a meal, but I don't want to take the time to hang around with him, plus I need the money to feed myself.
In terms of community service, I can be at peace in my private reflections on God and how much he loves me. But the trenches of community service can easily disrupt that peace. When I was at Harvard, I worked at a church for my field education, and I was involved in a "Summer Meals Program" for low-income children. I had to endure kids who didn't listen to me, a staff that didn't like me, my propensity for making mistakes, and just all out stress and chaos! Yet, the pastor said that it's in the stuff of real life that God is present (even though there were times when he looked like he was about to have a nervous breakdown himself!).
In the Gospels, the disciples enjoy times of rest, but they also go out to make the world a better place, though healing, exorcism, encouragement, etc. They perform the basic Christian duty of helping others. The Bible is clear that we should practice our faith and serve God with our actions (e.g., alms, giving to those who seek our help, etc.). We have an opportunity to express our faith in God when we so act. But I still wonder how to bring my warm, fuzzy, feel-good piety into the chaos of day-to-day life, where the world isn't always nice and good.