However, even if they were gay, I don't think that that's a sin, especially not a sin worthy of expulsion.
Well, you obviously are not of the Christian faith, and/or don't believe in biblical teachings. However, those that administrate that LUTHERAN high school, do believe in the bible, and do teach the Christian faith. They also are a PRIVATE organization, not a public one, and therefore have the right to do as they please regarding their "clientele", and their behavior.
I suspect highly that if a couple of heterosexual students were overt in unseemly behavior, they too would be reprimanded or expelled at some point if the behavior did not stop. Example, engaging in long passionate kisses and getting handsy in the hallways between classes. How long do you think that would be tolerated? And I'll bet those students don't swear much in that school, at least not where they can be heard by anyone in authority, as that would not be tolerated either. Either you are choosing to go to that school and are willing to abide by its rules, or you aren't. If you aren't, you choose another school.
These kids could go to a public school where most bad behavior is now tolerated, and let's see how those kids turn out when they reach adulthood. Probably another gay couple adopting non-gay children and then warping their children into further acceptance of their "lifestyle." Lesbians are a minute percentage of the population, if 1/2 of one percent, I'd be surprised. Probably less. So, for that deviancy, and it is a deviancy, including their behavior, everyone else should be forced to accept their lifestyle, whether they agree with it or not. The usual tyranny of the minority.
So, let's say the Lutheran school loses in court. This, of course, would be a flagship case, probably go all the way up to the Supreme Court, where Justice Kennedy (if Alito gets on the court) will become the new swing vote, and will probably side with the girls. Now you will have established law, and all religious schools will end up pretty much having to accept any overt behavior that students might choose to engage in, or risk being hauled into court. Effectively, you no longer would have religious schools; rather, public schools operating under the guise of being religious ones. Religious schools then would have 2 choices, accept the edict of the court, or close shop. I for one, would like to see ALL of the religious schools close shop in protest of such a decision, and then let's see what would happen. In my opinion, relgious schools cannot allow this precedent to be set, or they lose their character entirely, the first amendment would be breached bigtime, and it would mean that the courts dictate what private businesses can and cannot do, all or any of them.
So, bottom line, don't be so quick to be so liberal about these two girls' behavior, and you know it had to be overt or it wouldn't have come to anyone's attention. The chain of events that would follow could be devastating, both to religious institutions, and to our country's values. The devil will have won, and our country will continue its long and continuing decline into moral decay. And our country will be legislated by the courts, not the will of the people. We are losing our country, one accepted deviant behavior at a time.