From personal experience with dear friends and family members, one of the most common biblical justifications I’ve heard for homosexual practice is that Jesus himself never taught on it. The argument goes something like this: “What I cannot fathom is why Christ never spoke on the topic. While he spoke on the subject of marriage between men and women, this does not necessarily condemn same-sex sexual activity. Perhaps it’s progressive to think this way, but if it was truly important, don’t you think our Savior would have addressed it?”
Upon first impression, it does seem odd that Jesus doesn’t say anything explicitly about homosexual conduct in the Gospels. However, the assumption that Jesus never spoke on the matter may be unwarranted. Perhaps he did, but the evangelists (the authors of the four canonical Gospels) simply didn’t know about it or see any reason, given their intentions in writing, to record any of it. Not all that Jesus did or said, after all, was recorded by the evangelists (see John 21:25; cf. Acts 20:35, which records certain “words of the Lord Jesus” that are lacking in any of the four Gospels). Still, the lack of any explicit statement in the Gospels about homosexuality points to the ad hoc nature of those documents, or even to that of Jesus’s ministry. That is, the silence suggests not that Jesus found the topic unimportant, but rather that it wasn’t a controversial issue in first-century Palestinian Judaism, that Jesus never encountered the issue during his ministry, or that he had no need to qualify the conventional Jewish view at that the time, which was unmistakably based on the Jewish Scriptures (what we recognize today as the Old Testament or Hebrew Bible). As biblical scholar Craig Keener writes, “Jewish people usually viewed homosexual behavior as a pervasively and uniquely Gentile sin” and “regarded homosexual behavior as meriting death . . . or punishment by God in the afterlife.” Not surprisingly, the fact that same-sex intercourse was not uncommon in Greco-Roman society, especially in Greek society, explains why Paul, the Apostle to the Gentiles, deals with the issue directly on three separate occasions (Romans 1:26–32; 1 Corinthians 6:9–11; and 1 Timothy 1:9–10).
It is certainly right to suggest that Jesus’s explicit teaching on the subject of heterosexual marriage does not in and of itself necessitate his condemnation of homosexual practice. However, given his apparent acceptance of the conventional Jewish view on the matter, and given his explicit endorsement of heterosexual monogamy (see, for example, Mark 10:1–12) and chastity in singleness (Matthew 19:11–12), Jesus likely did think of homosexual behavior as sinful and contrary to the divine purpose for human sexuality (cf. Genesis 1:27–28; 2:20b–24).
Moreover, there is good reason to think that Jesus did address the topic implicitly at least on one occasion. That is, when Jesus states in Mark 7:21–22, “For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder, adultery,” etc., the Greek term he uses for “sexual immorality” here, porneiai (plural), is a comprehensive reference to various kinds of unlawful sexual intercourse, likely inclusive, in this context, of homosexual sex. Elsewhere, the noun frequently refers to adultery and prostitution (though note that it probably doesn’t refer to adultery here, since “adulteries” [moicheiai] is explicitly listed merely three words later), but can also refer to incest, bestiality, and same-sex intercourse. According to New Testament scholar Robert A. J. Gagnon, “No first-century Jew could have spoken of porneiai . . . without having in mind the list of forbidden sexual offenses in Leviticus 18 and 20 (incest, adultery, same-sex intercourse, bestiality).” If all of this is true, and if the authenticity of this text is assumed, then it follows that Jesus taught that homosexual sex, among other kinds of immorality (not least heterosexual sins!), “defiles” those who engage in it (Mark 7:20, 23).
 Craig S. Keener, “Adultery, Divorce,” in Dictionary of New Testament Background, ed. Craig A. Evans and Stanley E. Porter (Downers Grove, IL: InterVarsity, 2000), 15. David E. Garland concurs: “Though homosexual acts were generally accepted in the ancient world, Hellenistic Jewish texts are unanimous in condemning them and treat them and idolatry as the most obvious examples of Gentile moral depravity” (1 Corinthians, Baker Exegetical Commentary on the New Testament [Grand Rapids: Baker Academic, 2003], 213). Garland proceeds to cite multiple Hellenistic Jewish texts (see note 31 on the same page), including Wisdom of Solomon 14:26; Letter of Aristeas 152; Philo, On Abraham 26–27 §§135–37; On the Special Laws 3.7 §§37–39; Hypothetica/Apology for the Jews 7.1; Josephus, Against Apion 2.25 §199; 2.38 §§273–75; 2 Enoch 10:4; 34:2; Pseudo-Phocylides 3, 190–92, 213–14; Testament of Naphtali 3:4; Sibylline Oracles 2:73; 3:185–88, 764; 4:33–34; 5:166–167, 386–433, 595–600, 764; and Testament of Jacob 7:20.
 This is true of both classical Greek and rabbinic usage, as well as New Testament usage. See H. Reisser, “porneuō,” in The New International Dictionary of New Testament Theology, ed. Colin Brown (Grand Rapids: Zondervan, 1986), 1:497–501; and Gottfried Fitzer, “porneia, as, hē,” in Exegetical Dictionary of the New Testament, ed. Horst Balz and Gerhard Schneider (Grand Rapids: Eerdmans, 1990), 3:137.
 Robert A. J. Gagnon, The Bible and Homosexual Practice: Texts and Hermeneutics (Nashville: Abingdon, 2001), 191. For another potential implicit reference to homosexual behavior on Jesus’s part, see pp. 192–93 in Gagnon’s book.