Though the Bible does not directly speak about bisexuality, it frequently addresses issues related to sexual ethics. A look at some of these principles offers clarity regarding God's view of the practice of bisexuality.
Does the Bible say anything about bisexuality? Is being bisexual a sin?
First, sexual relationships were created by God to take place within the context of marriage between a man and a woman. Genesis 2:24 teaches, "Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh." Though the Bible records other forms of relationships, it only specifically presents one man and one woman enjoying sexual relations within marriage as God's design.
Second, since bisexuality includes sexual relationships outside of marriage, it is also excluded as a form of sexual immorality. First Corinthians 6:18 clearly teaches, "Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body."
Third, bisexuality is also excluded from Christian practice since it includes same sex relationships that are prohibited in the Bible. In the Old Testament, same sex activity was called an abomination (Leviticus 18:22). In the New Testament, Jesus speaks directly of marriage (and sexual relations) between one man and one woman in marriage (Matthew 19). The apostle Paul mentioned that some of the believers in Corinth had been involved in same sex relations before becoming believers, saying, "And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God" (1 Corinthians 6:11). Same sex activity is clearly excluded from the lifestyle of those who follow Christ. This would certainly also include bisexual relations.
A brief word should be mentioned regarding the distinction between temptation and practice. Some people claim they have desired same sex or bisexual relationships since a young age and that they were therefore "born" that way. While it is unclear if this is the case, it does not mean bisexual or same sex relationships are acceptable for believers in Christ. A person may be tempted or have thoughts or inclinations toward various actions, yet these desires must be evaluated to determine whether they are consistent with God's teachings. When a desire is inconsistent with God's will for our lives, it should not to be acted upon.
Bisexual relations are certainly outside of God's plan for human sexuality according to the Bible. While Scripture is clear that unbelievers are sometimes involved in such practices, believers in Christ are commanded to live differently. In addition, believers are called to show kindness and grace to those they meet who may be involved in such practices in order to share the good news of Jesus (John 3:16) and help others to experience the perfect love that only God can provide.
Is homosexuality a sin?
Does the Bible say anything about transsexualism / transgenderism? Is gender dysphoria / gender identity disorder the result of sin?
Are all sins equal?
Does my private, personal sin affect others?
How can I have victory in overcoming sin?
Truth about Sin