the problem i see personally with "sin" being infinite is because it is "something" that can be taken away, forgiven or whatever. it's something that doesn't have an eternal foundation cause it was created...whether by God as described in Isaiah 45:5-7, or created by free-will of human beings or using free-will to believe in Lucifier's pre-meditated advice (cause in all actuality, i wonder if the devil was right, but i think we can see more why God commanded Adam and Eve to not do it...looking at it from a literal pov.) so here we have finite beings, createing something for the first time in the story. they knew nothing and if people consider them perfect, then ignorance is truly bliss cause Adam and Eve were probably the last truly ignorant people alive.
point is, sin was created. it has a beginning. anything infinite, by sheer definition doesn't have a beginning.
and a finite creature, solely based in a temporary vessel, going to die someday, having nothing of infiniteness has no possible way of doing an infinite action. it's not in our makeup/or our design. God can destroy the soul, it's in his "jurisdiction" cause he's omnipotent, doesn't mean He will do it, just means He can. so our whole entire makeup is that of a finite design. we have a beginning and we have an end. and it seems that anybody who thinks they can commit an infinite crime against the Almighty, resembles Lucifier in my opinion...someone with their buckle strapped too tight around the waist that they think they can do anything against the Almighty.