Sorry, science doesn't work that way. It's your job to give evidence that some sort of afterlife exists.
To not believe in afterlife, you explicitly have to not believe it, so even the denying of afterlife is based on a (negative) faith.
Atheists don't seem aware of being their position a simple negative faith response to a positive faith.
But "weak" atheism is merely a rejection of theism. It is not a proposed hypothesis, but a rebuke of unsupported hypotheses.
All things that happen must have a cause.
Even Big Bang had its Cause. And since the exact definition of God is: "The only one not caused by anything, but simply 'cause' of Itself", there's no escape here...