Crisis of faith? Most atheists have had that, since most of us were brought up in some faith or other, to a greater or lesser degree!
But religious people do speak of a crisis of faith. What do they mean by that? It sounds like ours viz. something happens which tends to prove the illogicality of the belief. Why should you continue to believe what you've been taught or come to believe if the evidence now disproves it, or casts such doubt upon it that it no longer seems likely, or that observation shows it inconsistent ? We don't do it in other areas of life, or we hope not to. (All areas of knowledge contain examples of people who stubbornly maintained disproved theories)