It is just too neat, I suggest, to confine Romans 14 and 15 to matters of 'secondary' importance and be done and dusted with its relevance to contemporary discussion and debate over homosexuality.
When Paul writes in Romans 15:7, "Welcome one another, therefore, just as Christ has welcomed you, for the glory of God," he is placing our welcome of one another on the same level of importance as Christ's welcome to us. That is, if salvation, Christ's welcome of us, is a 'primary' matter of doctrinal importance, so is our love for one another (cf. a major theme in 1 John around God's love for us and our love for one another).
The issues in Romans 14 and 15 are also of primary importance because they have the potential to 'destroy the work of God' (14:20). In our current discussions we are talking about our welcome of one another and we have huge potential to destroy the work of God in how we handle these discussions. I stand by my assertion that Romans 14 and 15 is relevant to the situation at hand.
In catching up on where debate on this blog has gone over the last week, with a strong and robust critique of what I have said, including what I have said with less clarity than I would have wished to have achieved (!), I nevertheless continue to see analogies between the situation in Rome and our situation today.
Principally, there the Christian community was divided over the evaluation of a course of action. For some, eating certain foods was wrong because those foods were unclean. For others, all foods were clean so everything could be eaten. Paul, in his own mind, was clear on which side of the dispute he belonged: "I know and am persuaded in the Lord Jesus that nothing is unclean in itself" (14:14). But what he does not then do is engage in an attempt to persuade those on the other side to change their minds. Rather he engages in a powerful, subtle plea to those who agree with him to live in such a way that they do not make their brothers and sisters on the other side of the dispute to stumble: "Do not let what you eat cause the ruin of one for whom Christ died (14:14) ... it is wrong for you to make others fall by what you eat; it is good not to eat meat or drink wine or do anything that makes your brother or sister stumble" (14:21).
One analogy, I suggest, is that today in the Western church we have a powerful, strong group of theological and ministerial leaders who think that nothing is wrong in itself in respect of sex between any two people in a loving, committed, permanent relationship. As I read their arguments they would happily say, "We are persuaded in the Lord Jesus that this is so." The continuing analogy then would be that Paul would say to them, "Do not let what you affirm re sexual relationships cause the ruin of one for whom Christ died." Incidentally, I recognise that the chances of this particular group of the "strong" having regard in this Pauline way for those who think differently (the "weak") is zip!
But there is another analogy to consider, one which focuses less on any analogy between clean and unclean food and more on analogy between the church divided into "strong" and "weak" groups. For the Western church is divided at this time (indeed, all churches, as far as I can see) in another way over homosexuality (with the possible exceptions of a very few ultra-liberal churches). In this division the "strong" are those for whom the normative experience of life, of being Christian and of organising domestic households is innately heterosexual: husband and wife; mum and dad; boyfriend and girlfriend. In my personal experience of church this is the mainstream, overwhelming presentation of congregations to the point that single people (whether identifying themselves in any further way or not) often grizzle that church life is all about families. The "weak" then are the tiny or even invisible minority who openly identify as gay or would do so if they felt brave enough in the midst of the overwhelming majority to do so. (The "weak" are also those who are single). The analogy then would be that Romans 14 and 15 speaks to us of the ways in which those who belong to the "strong" can cause their brothers or sister who belong to the "weak" to stumble.
Consider this, as one instance: everything we discuss about Scripture and its meaning for our lives is clean (nothing is forbidden for discussion) but the ways in which we discuss things, the manner in which we emphasise some parts of the Bible and not others, the priority we give to some issues and not to others can be a stumbling block to others. A question about homosexuality in these times is whether the Bible requires us to make it the major issue we have made it. By making it a major issue (when, arguably, the major issue of our times is the breakdown of marriage among Christians) are we making a stumbling block for the "weak"?