And is Saint John of Damascus any more correct than saint Harley of Virginia? I think the answer is obvious. He has sufficiently refuted the idea that the passage you and others are so fond of parading around as proof of sex actually proves nothing of the sort. And more to the point, he did it with ease. So, when you say we will have a difficult time with Matt.1:25, I can honestly say this:
"No, not really."
I should point out Saint John's of D argument is exactly the argument John Calvin suggest, namely that the word "till" doesn't necessarily mean that Mary had relationships after the birth of Christ. I find this a very weak argument simply because there is no reason for Matthew to have included that clause. Instead of:
"but kept her a virgin until she gave birth to a Son; and he called His name Jesus." Matt 1:25
it should have read:
"but kept her a virgin and he called His name Jesus."
This coupled with the fact that
1) our Lord Jesus' "brothers" are defined in scriptures (Matt 12:46, 13:55, Mark 3, Luk 8, John 7, etc), 2) Paul refers to our Lord Jesus' "bothers" (1 Cor 9:5),
3) our Lord Jesus minimizes Mary's role to the role of all believers (Matt 12), and
4) the term cousin (often used as an argue as to what is meant here) is used in Col 4:10.
I think the scriptural evidence is a bit overwheming.