Paul is referring to the sin and death of the first human and all of his descendants. Adam sinned and he and all of creation, both in the sky above and on Earth, died. The whole cosmos started falling down that elevator shaft. Your question left out the fact that we were all born damned. Whether or not one believes that there is a God, judgment, angels, devils or hell doesn't have much to do with it.
Death is actually the evidence of our problem.
Death is the proof that we are in need of salvation. Good behavior will not save us. One can not avoid death by being good. Believing that there is a God won't save anyone. Those who face hell do so because they rejected the salvation offered through Jesus Christ.