I agree with Ren, but if you are serious about considering Cornell, you can look into the following resources. Cornell has many very active and supportive religious communities, from Wiccan to Jewish, Christian to Hindu:
I'm assuming that you are a Christian of the non-Catholic persuasion:
Home | Chesterton House Cornell Navigators Cru @ Cornell - cornellcru.com Cornell Christian Fellowship Measureless
I would email these groups and ask them about the strength of their communities.
You should be aware, however, that Cornell is a very diverse and energetic university, filled with all types of people from all types of backgrounds. And people tend to be a bit vocal -- expect your faith to be challenged in one way or another, and don't always expect people to be polite to you about your faith. JollyStNick, case in point.
The campus this semester has been in uproar over a couple of religiously sensitive issues, including the ouster of a gay student from a leadership position in a Christian organization and a memorial for Palestinian victims of Israeli aggression.