These questions have been polarizing for many in the western world. Mostly because they touch close to home. We may be personally dealing with these questions or have someone we love dealing with these questions. The purpose of this answer is to clearly present the orthodox “biblical view”.
Gender
Scripture tells us that God created only two genders (male and female) that are assigned to human beings at the point of conception. (Gen 1:27-28, 5:2; Matt 19:4; Mark 10:6)
What is Marriage?
Biblical marriage is a covenant that can only be made between a male and a female and God. This covenant creates a “one-flesh” relationship. Biblically, there is no room for same-gender marriages. While they may be affirmed by governments for tax purposes, or even some pastors and churches, there is no biblical precedence to confirm God’s affirmation of such unions (Gen 1:27-28, 2:24, 5:2; Mark 10:6-7; Eph 5:31). In fact, we actually have the opposite.
In Genesis 6:5 we read in the flood narrative that for the average person in Noah’s day “every intent of the thoughts of his heart was evil continually.” The Midrash and the Babylonian Talmud, both ancient Jewish commentaries on the Bible, tell us this phrase refers to the historical fact that communities wrote marriage documents for the union of male couples and was one of the reasons for the flood. (Midrash – Genesis Rabbah 26:5; Leviticus Rabbah 23:9; Babylonian Talmud – Chullin 92ab) See also (Mishneh Torah – Issurei Bi’ah 1:14, 21:8, 21:18)
Similarly, Hebrew Law given by God through Moses calls homosexuality an “abomination” that was punishable (Leviticus 18:3, 18:22, 20:13, Deuteronomy 23:17). The Mishmash fo Sifra Aharei Mot 8:8-9 states that in Egypt, homosexual marriage was common but God calls in the Law for His people not to practice what they had seen in Egypt.
Sexuality
Biblical marriage has the benefit of companionship, pleasure, fulfillment, and procreation. This is the context in which marriage partners can participate in lifelong sexual monogamy. Scripture states that participation in any sexual practice outside of this tradition is called sin. This includes incest, adultery, homosexuality, immorality, pornography, etc (Romans 1:24-27; 1 Cor 6:9-10, 6:18-20, 10:8; Gal 5:19-21; Eph 5:3; Col 3:5; 1 Tim 1:9-10; 1 Thess 4:3-7; Heb 13:4).
In Genesis 18-19, we are told that God destroys Sodom & Gomorrah because of their immorality, including their practice of homosexuality. From this time forward, homosexual activities are called sodomy and practitioners of sodomy called sodomites (Genesis 18:20, 19:5). We are told that “Godly kings” removed sodomites from the land (Asa in 1 Kings 15:11-12; Jehoshaphat 1 Kings 22:46; Josiah 2 Kings 23:7) and “wicked kings” allowed sodomites to flourish (Rehoboam 1 Kings 14:24).
Can a person be born with same-gender attraction?
There is no specific biblical verse that suggests a person can be born with a propensity toward same-gender attraction. There is biblical evidence that we are all born with the propensity to sin (Ps 51:5) but we all have a choice to yield or resist temptation in our life.
Romans 1 teaches that homosexual behaviour arises as a result of the choice to reject God as He is and worship a self-imagined “god” (Romans 1:16-32). The idea in this chapter is that self-worship spirals into same-gender thoughts, feelings, and actions. It is insinuated that God allows us to become what we worship. When we worship anything less than Him, we are given over to degrading thoughts, feelings, and behavior. This can then develop into a pattern of thinking that affects behavior.
The Bible teaches that those who surrender to Christ can have thoughts renewed (Romans 12:1) and find the power to refrain from sexual immorality of any kind. (Romans 2:1-3; 1 Corinthians 6:11)
How ought a follower of Jesus treat a person who practices same-gender sexuality?
If a person is not a follower of Jesus, Christians are told to walk humbly with balancing truth and love, realizing that we all need the saving work of Jesus (Romans 2:1-3). Believers are called to treat everyone who does not follow Jesus the same way. Jesus is the one who saves and the one who will judge each person at the end of time. However, keep this one thing in mind. Believers are called not to associate with others who say they are Christians and openly and defiantly engage in sexual immorality of any kind or support those who do (1 Cor 5:9-13).