I get asked, occasionally, how I hold both of these together — Marcus Aurelius on one shelf, Scripture on the other, without either one canceling out the other. The honest answer is that on the question of contentment specifically, they're not nearly as far apart as their reputations suggest.
Stoicism draws a clean line between what's within your control and what isn't, and locates peace entirely on your side of that line. You don't control outcomes, other people, or most of what happens to you — you control your judgment of it, your response to it, your character in the middle of it. Contentment, for a Stoic, is largely a discipline of attention: keep your focus on the part of the field that's actually yours to play.
Scripture gets to a similar place by a different road — not through self-discipline alone, but through trust. Paul's line about having learned to be content in any circumstance wasn't a philosophical technique he mastered. It came out of an actual, lived dependence on something outside himself, which is a meaningfully different foundation than pure self-governance, even if the resulting posture looks similar from the outside.
Where I find them most useful together is exactly there — Stoicism supplies the discipline, the practical daily work of not being yanked around by every circumstance; faith supplies the reason that discipline doesn't collapse into mere stoicism-as-stubbornness. One tells you what to do with your attention. The other tells you why it's safe to let go of what you can't control in the first place.
Neither tradition, taken seriously, tells you contentment is easy. Both tell you it's available, right now, regardless of your circumstances — which is a much larger claim than it sounds like, and one worth testing rather than just admiring.