"I was raised (insert religion here)..."

OK, how do you feel when someone admits they had a particular faith during their upbringing but discarded as they got older, like some kind of jacket that tightens as you grow and then you throw off? (Parental restrictions are a little like that too, but shh...)
Me, I get bummed... for all of five seconds. If you care about this sort of thing, you'll want to know, why? And you'll have a fleeting sense of sadness that one of the flock has turned away, if the faith rejected happens to be yours. More than one author has admitted to some kind of Christian upbringing; question is, did they simply subscribe to some intellectual idea, or actually walked the walk it demands (down the Via Dolorosa no less)? Some observations are in order:

1. It's none of your business. As Aslan in The Chronicles of Narnia tells Lucy in The Voyage of the Dawn Treader, "I tell no one any story but his own." He echoes his real-life self in John 21: "What is that to you?"
Yeah, sure. But I want to know, why? Fine, ask them. But don't make it a goal in itself--it is when you go to secondary sources, gun for info whenever you can, make such an issue of his eternal life you forget your own.
In short, if God wants you to know, He will let you.

2. It's all of their business. Islamic zealots aside, I don't believe you should go beyond your normal routine. Sure, bring up the gospel now and then--in fact, a person who has been going to church all his life and decides to stop because he genuinely does not believe what is said from the pulpit may be closer to the spirit of Christ than he ever was before (C.S. Lewis, Mere Christianity).

3. It's a caricature. George W. Bush may be pictured as a six-shooter-toting cowboy with slit-eyes, a large nose and larger ears, but no one in his right mind would think that was a true-to-life picture of the American president. In fact, I think the "I was raised..." syndrome has the person seeing such a caricature--"That can't really be the President!"--but that is not the same as "The President is not George W. Bush because someone drew a bad picture of him."

4. It's the Lord who saves, not you. Of course, get sad. But shake it off--unless the rejecter is someone intimately related, someone whom you'd love to spend eternity with. After death (which quite unfortunately may be around the corner) it will be too late!
Pray. For wisdom, for protection--the Lord is willing that all should come to repentance. When is not so important as how.