Romans 1:26-27 is clearly about same-sex relationships.
Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion. (Romans 1:26-27, NIV)
But it is also clearly not about all same-sex relationships. How so? Read the verses in context.
The people knew God but did not glorify him or honour him, and their heats were darkened.
For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. (Romans 1:21, NIV)
Claiming to be wise they became fools and started worshipping idols made in the image of people and animals.
Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles.(Romans 1:22-23, NIV)
Then God gave them over to sinful sexual desires.
Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. (Romans 1:24, NIV)
Then the truth about God was replaced with idolatry.
They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator—who is forever praised. Amen. (Romans 1:25, NIV)
Then, because of what they had done before, God gave them over to shameful lusts.
Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion. (Romans 1:26-27, NIV)
And finally, their rejection of God was complete, and they became very wicked.
Furthermore, since they did not think it worthwhile to retain the knowledge of God, he gave them over to a depraved mind, to do what ought not to be done. They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents; they are senseless, faithless, heartless, ruthless. Although they know God's righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them. (Romans 1:28-32, NIV)
The depravity described in verses 26 and 27 (and verses 28 to 32) is part the process of rejecting God and descending into idol worship and wickedness. One step follows another. It does not describe same-sex relationships among Christadelphians. How could this passage describe gay Christadelphians when Christadelphians glorify God and give thanks to him (step 1)? How could this passage describe gay Christadelphians when no Christadelphian is an idol-worshipper (step 2)? How could this passage describe gay Christadelphians when no Christadelphian has exchanged the truth of God for a lie (step 4)? Gay Christadelphians have not passed through steps 1, 2, 3, and 4. To say that step 5 describes Christadelphians in same-sex relationships is taking verses 26 and 27 completely out of context.
There is a possible link between Romans1:21-32 and 1 Kings 14:24. As we have seen, Romans 1 has a connection between false religion and sexual immorality. That same connection is found in 1 Kings 14:24.
There were even male shrine prostitutes in the land; the people engaged in all the detestable practices of the nations the LORD had driven out before the Israelites.(1 Kings 14:24, NIV)
The "male shrine prostitutes" were temple prostitutes. They are very similar to the men described in Romans 1:27. The Hebrew word is qadheshim.
This King James Version translation of this verse is significant.
And there were also sodomites in the land: and they did according to all the abominations of the nations which the LORD cast out before the children of Israel. (1 Kings 14:24, KJV)
The KJV's use of the word "sodomites" here is now universally acknowledged as a bad translation, and the phrase "male cult prostitutes" is much more accurate. The same applies to Deuteronomy 23:17, 1 Kings 15:12, 1 Kings 22:46, and 2 Kings 23:7 where qadheshim is used in the Hebrew.
The "unnatural relations" described in verses 26 and 27 are described as "shameful". Does this indicate that all same-sex relationships are shameful? No. In step 3, verse 24, sexual activity is described in a negative way: "sexual impurity", "degrading their bodies". But same-sex relationships are not described until verses 26 and 27, so verse 24 must be describing opposite-sex relationships. When we read verse 24 in context, we see that it is not describing all opposite-sex relationships, just the immoral opposite-sex relationships of the idol-worshippers. In context, it is clear that verses 26 and 27 describe the immoral same-sex relationships of the idol-worshippers as well, not all same-sex relationships.
Now we must look for examples of same-sex relationships that the Bible approves of. We must look for Biblical Affirmation.
Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world
Matthew 25:34, NIV