This is still based on faith. No logic can prove it right or wrong. However, some experiences and knowledge we get while we live can give hints. Otherwise it's like "I've not seen/experienced presence of God therefore there is no God". ('The fool says in his heart, “There is no God.” ' Psalm 14:1)

(well, some people claim they experienced deaths and reincarnations, but this is still a matter of trust and faith)