Atheists: at the risk of being deleted...again?

What is the difference between the theory that life was caused by abiogenesis, and the theory that life was caused by an intelligent designer? Both theories lack any physical evidence. So why is abiogenesis accepted and creation by an intelligent designer rejected? Someone argued, "If God created life, why isn't He still causing spontaneous creation?" I countered, "If abiogenesis caused life, why isn't IT still turning non-living matter into living matter?"