Can Christians agree to disagree on the issue of same-sex practice?
The Bible allows for disagreements on certain issues, so in Romans 14, for example, Paul speaks of 'disputable matters' and calls on his readers to be convinced in their own minds (Romans 14:5). There are, however, other truths which are non-negotiable - these are sometimes called 'gospel issues', i.e. significant matters upon which Christians can't simply agree to disagree because they impact our understanding of the gospel and, therefore, our salvation. The question is, into which category does same-sex practice fall?
In 1 Corinthians 6:9-11, Paul makes it clear that same-sex sexual behaviour is one mark of unrighteousness and warns that those who consistently and continuously live in the kinds of ways listed in that passage (i.e. with no evidence of repentance) won't inherit the kingdom of God. There are also other Bible passages which warn of the dangers of sexual immorality and strongly rebuke false teachers who lead people into sexual immorality (e.g. Jude 4, Revelation 2:20-22).
In light of these passages, as well as the Genesis 2:24 principle that the only God-given place for love and attraction to express themselves sexually is in a marriage between one man and one woman, we see that the Bible is clear that the morality of same-sex sexual practice is not a secondary issue over which Christians can simply agree to disagree.
Resources for further study
Please note that the external resources below are intended to complement the main answer given above and may not entirely match TFT's position.