The Gentiles were to abstain from three items: (a) food polluted by idols, (b) sexual immorality, and (c) the meat of strangled animals and … blood. Many Bible teachers say these are only ceremonial matters. The food polluted by idols is explained in verse 29 as “food sacrificed to idols” (cf. 22:15). This then, it is argued, looks at the same problem Paul discussed (1 Cor. 8–10). The abstinence from sexual immorality is explained as referring to the marriage laws of Leviticus 18:6–20. The prohibition against eating blood is taken to refer to Leviticus 17:10–14. All three prohibitions according to this interpretation look back to the Jewish ceremonial Law.
However, it seems better to take these as moral issues. The reference to food polluted by idols should be taken in the sense of Revelation 2:14, 20. It was a usual practice among Gentiles to use an idol’s temple for banquets and celebrations. Paul also condemned the practice of Christians participating in these (1 Cor. 10:14–22). Fornication was such a common sin among the Gentiles that it was an accepted practice. The problem of immorality even persisted among Christians all too often, as is witnessed by the New Testament injunctions against it (cf. 1 Cor. 6:12–18, where Paul was evidently answering arguments in favor of immorality). The third prohibition goes back further than Leviticus 17; it looks back to Genesis 9, where God established the Noahic Covenant, a “contract” still in effect today. There God gave people the privilege of eating flesh but the blood was to be drained from it.
All three prohibitions in Acts 15:20 are best taken in an ethical or moral sense. If this be so, they are still the responsibility of Christians today, even to the point of not eating blood sausage and raw meat. By not attending temple banquets, or being involved in fornication, or eating meat with blood in it, the Gentile Christians would be maintaining high moral standards and would keep from offending their Jewish brothers. There were Jews in every city who would be offended by Christians not following these strictures. These Israelites were well acquainted with these moral issues.
Stanley D. Toussaint, “Acts,” in The Bible Knowledge Commentary: An Exposition of the Scriptures, ed. J. F. Walvoord and R. B. Zuck, vol. 2 (Wheaton, IL: Victor Books, 1985), 395–396.