I just had to check this article too, and I find the meanings for the origins of sin “existing, real, true” and “guilty.”

so the Finnish word “synti” =”sin” origins in “synty” meaning “birth; genesis” is even more like “sin” of the above mentioned meanings..

And what makes me laugh, here looking for distant or far fetched (sorry my perfect English if I make mistakes.. English is not my native language) explanations.. The Finnish word “kiltti”, that is pronounced just like “guilty”.. is an adjective meaning “obedient, nice; tender character..”

I might think, that in the Finnish language the original meanings of the words are saved like in a refrigerator.