The Greek of Acts 17:22 reads:
Σταθεὶς δὲ [ὁ] Παῦλος ἐν μέσῳ τοῦ Ἀρείου πάγου ἔφη· ἄνδρες Ἀθηναῖοι, κατὰ πάντα ὡς δεισιδαιμονεστέρους ὑμᾶς θεωρῶ.
While older translations render the term δεισιδαιμονεστέρους (the accusative masculine plural comparative adjectival form of δεισιδαίμων) as either "[too] superstitious" (e.g., KJV) or "given up to demon worship" (e.g., Darby), modern translations correctly translate the term as "[very] religious":
Then Paul stood in front of the Areopagus and said, "Athenians, I see how extremely religious you are in every way" (NRSV)
So Paul stood in the midst of the Areopagus and said, "Men of Athens, I observe that you are very religious in all respects" (NASB)
So Paul stood there in the middle of the Areopagus and said, "Men of Athens, I see you are very religious in every respect" (Lexham)
So Paul, standing in the midst of the Areopagus, said: "Men of Athens, I perceive that in every way you are very religious" (ESV)
So Paul then stood up in the meeting of the Areopagus and said: "People of Athens! I see that in every way you are very religious!" (NIV)
So Paul stood before the Areopagus and said, "Men of Athens, I see that you are very religious in all respects” (NET)
Modern Greek lexicons support this translation of δεισιδαίμων. BDAG, while referencing Acts 17:22, defines it thusly:
1760 δεισιδαίμων
• δεισιδαίμων, ον, gen. ονος can, like δεισιδαιμονία, be used in a denigrating sense ‘superstitious’ (cp. Maximus Tyr. 14, 6f in critique of the δ. as a κόλαξ ‘flatterer’ of the gods μακάριος εὐσεβὴς φίλος θεοῦ, δυστηχὴς δὲ ὁ δεισιδαίμων [s. H. app. and T.’s rdg.]; Philo, Cher. 42; s. Field, Notes 125-27), but in the laudatory introduction of Paul’s speech before the Areopagus Ac 17:22 it must mean devout, religious (so X., Cyr. 3, 3, 58, Ages. 11, 8; Aristot., Pol. 5, 11 p. 1315a, 1; Kaibel 607, 3 πᾶσι φίλος θνητοῖς εἴς τ᾽ ἀθανάτους δεισιδαίμων) comp. for superl. (as Diog. L. 2, 132): δεισιδαιμονεστέρους ὑμᾶς θεωρῶ I perceive that you are very devout people Ac 17:22 (the Athenians as the εὐσεβέστατοι τ. Ἑλλήνων: Jos., C. Ap. 2, 130. Cp. Paus. Attic. 24, 3 Ἀθηναίοις περισσότερόν τι ἢ τοῖς ἄλλοις ἐς τὰ θεῖά ἐστι σπουδῆς).—DELG s.v. δαίμων. TW. Spicq.
Here we see that, while the term can be used in a negative sense (“superstitious”), in the context of Acts 17:22 and Paul’s speech to those in Athens, it is used in a positive sense as captured in modern translations of the verse, especially as, per the context, Paul is "buttering up" his audience.
I bring up this as it is very odd and “un-Calvinistic” if you will for Paul to laud the religious devotion and belief of unregenerate individuals who, in the Calvinistic perspective, were totally depraved idolaters who knowingly were rebelling against their innate knowledge of the Tri-une God(per the Reformed understanding of Romans 1) and had nothing inherently good in them (again, per Total Depravity). If, however, one were to adopt a Latter-day Saint or some other non-Reformed (e.g., Arminian) understanding of the nature of fallen man, such is not problematic to one’s anthropology (theology of man). One other option is to accuse Paul of perverting the true Gospel and the depravity of man by (wrongly and sinfully) buttering up his audience, though I don't think many will go down that route.
For more on the theology of Acts 17, particularly vv.28-29, see: Latter-day Saint Theology and Acts 17:28-29 (cf. Is it problematic to cite Joseph Fitzmyer?)
On the anti-biblical nature of Calvinism, see, for instance:
