Before I start, I just want to be quite clear that I'm not trying to be contentious or antagonistic. I'm a person of a different faith, who accepts the plurality of faiths, and wants to live in peace and understanding with others.
My question is about Jesus's death atoning for your sins. Does he not atone for all sins past and future, so that others can believe in him and also receive this atonement? In which case, why do you need to behave ethically?