The most rational argument I’ve seen for belief in God (and the Christian version, in particular) is the “spiral argument” of Catholicism.
Much better, more rational, than anything I’ve ever seen among Protestants.
And I fail to see how any Protestant can listen to conversion stories like the one of Scott Hahn and not waver.
I listen every week to various conversion stories, on EWTN’s The Journey Home, e.g., and find it fascinating. Dunno why.
Related previous post: The Unidirectionality of Conversions