I swear!

How ironic that though swearing is a sin, many swear words contain references to God. Even something as innocuous as "Goodbye" is a derivative of the archaic sign-off "God be with ye".

Crikey; Jeepers Creepers - References to Jesus Christ
Cor blimey - God blind me!
Omigosh - Oh my God!
Holy cow; Holy mackerel; Holy guacamole - I have no idea how why they beatified the bovine, anointed the angler's choice, or glorified the gourmet bean paste
Sacre bleu (French) - sacred blue, meaning sacred heavens, or Good heavens!
What the heck; What the hell; What the fish - The first two are derived from heaven's counterpart, which might explain why they're slightly more popular. The last one is derived from a word I'd rather not say, but it rhymes with "duck".
Darn; Dang - Call a spade a spade: It's derived from Damn.