The argument that procreation within marriage is unimportant in relation to the growth of the kingdom of God is thus mistaken. Christian marriages are one of the main means by which the kingdom is populated.
The converse is also true. As Mary Eberstadt argues in her book How the West Really Lost God, a good case can be made out for saying that the decline of the Church in the West has been the result of the collapse of traditional family structures. As she puts it ‘family decline in turn helps to power religious decline.’ What this means is that those who are really interested in the growth of the kingdom of God should be seeking to support and encourage the traditional family and in particular the importance of having children rather than downplaying their significance.
Thirdly, there is nothing objectionable in principle in the argument that the Holy Spirit guides the Church through the witness of Scripture to discern truths that are not contained in Scripture itself. Scripture does not address every specific issue and situation which the Church faces during the course of its history and so the Church requires guidance by the Spirit which goes beyond what Scripture explicitly says although in accordance with it. 
However, in any given case it needs to be shown that the Church is actually being guided to discern truth. This means a persuasive case needs to be made out as to why what we know on the basis of Scripture leads us to view a new issue or situation in one way rather than another. In relation to the issue of same-sex marriage a case would need to be made out as to why the witness of Scripture leads us to believe that the Church should celebrate same-sex marriages in those jurisdictions, such as Scotland, where they are legal. As we have seen, the report fails to make out such a case. The report fails to show that there is anything at all in Scripture that points us in this direction.