Google is your friend and his.
There are many sites out there that explain the whole 'Gay is Ok' and tests the passages commonly used to persecute the gays.
I strongly suggest that he searches and reads. If you want to you can find a few sites and get him started - however the work of finding the information is more valuable than just the information itself.
I will give you the link to gay affirming churches:
http://www.gaychurch.org/find_a_church/f...church.htm
Find one or a dozen in your local area and see if you can get him involved in one of those. If he surrounds himself with Christians who do not take issue with the gay, he may be able to retain his spirituality and find peace of mind as well.
His folks are going to go through the 5 stages of grief (denial, bargaining, anger, depression and eventually acceptance). OK, they may never accept... however most parents do come to terms with it and accept it to one level.
They have the added bargaining chip of Christianity. So they have more fuel to throw on the fire of depression, denial, bargaining, anger....
If he looks up the passages in gay affirming manner, he may be able to present his case based on the bible to his folks and win their 'belief' that God is merciful and that what the church has been preaching for 2000 years is not altogether true.
Also, his venture in finding a gay affirming church may also provide him with support of clergy and other gay Christians who can help him deal with the spirituality/religious side of this matter. And they can, through demonstration, most likely show the folks that yes, A God Fearing Christian Homosexual is possible and we do exist.