No group should participate with ANYTHING to do with GLSEN.
GLSEN is about inducing children to engage in homosexual sex.
If this were any other adult they would have been in jail for attempting to solicit minors.
GLSEN and the GSA's use the same methods as child molesters. How any christian group can buy into them is beyond reason. The only way would be an inside job in the christian group.
That has happened. Gay seminarians have been very busy over the years.
One of the early successes racked up by gay groups in the mid-60's was to organize "colloquys" with mainline churchmen about the need for the churches to condemn condemnation of gays and to take a "reconciling" approach to ministering to homosexuals. "Reconciling" in the sense that gay activists mean it is different from what Christian usage has always meant (I'll let the Bible scholars speak to that one), but the way that gays mean it is that gays do not repent or admit wrongdoing, temptation, or any kind of problem whatsoever, but rather Christians back off their moral condemnations of homosexuality as sin and "accept" gays "as God made them" -- i.e., as practicing homosexuals -- within the Church's communion.
In my own opinion, those early conferences and "dialogue" groups were stacked by gay churchmen and activists as politically loaded, Delphi'd processes. People who dissented from the gay POV were not at all represented, I am morally sure, and the conferences and early groups (the first "gay-straight alliance" type front-groups) were a put-up job straight out of Saul Alinsky.
More recently, Methodists were surprised and horrified when a prominent bishop suddenly died of AIDS. And this man was a preceptor of the Methodist Church.
I call what the gays have been up to in the churches "ecclesiastical cow-tipping". The objective is to make the Church stand up and contradict Genesis and Leviticus on the subject of homosexuality, and the teaching of St. Paul and St. Jude in their epistles on the same subject, and that of Maimonides on "practices of Egypt."