Arguments Against Religion

This is always said about people healed of invisible maladies, such as cancer, mental diseases, heart problems, or other sicknesses.  Why does God never re-grow a lost limb?  Why is it that people KNOW that once they lose an arm, they will never get it back and that praying for it would seem stupid and absurd – but if they have cancer they pray for God to heal it?  Or, we can assume that if someone gets shot in the head with a shotgun, there is no amount of prayer that will bring that person back or re-grow skull fragments and brain matter.  More self-fooling and ridiculous thinking.  Even prayer is altered to align with a Christian’s world-view – and they don’t even see that.