It is logical because from the Baha'i standpoint heaven is nearness to God and hell is remoteness from Him. If one doesn't believe in God being 'near' Him would be rather difficult. However, I don't believe in an eternal anything other than an eternal soul. I believe we will continue to grow and develop in the next world.
Certainly.
I think the importance of this world is that, in a world where God isn't blatently obvious, we can choose to love God (which is simply another word for loving truth, loving kindness, loving all people), or we can choose to allow ourselves to fall into self-centeredness, anger and hostility, tribalistic thinking, frivolous wastes of time, and even hatred).
I don't see any distinction between an atheist who is genuinely committed to truth and charity and justice, and someone who is committed to a positive understanding of God.
Nor do I see a distinction between a spiteful, prideful, believer in "God" who looks down on others and disseminates division and discord, and a self-centered atheist who shoves others aside to get his. The words don't really matter, only the hearts and actions matter.
Every indication from near death experiences, Baha'i teachings, other religious teachings, etc. is that when we die many of the veils that make it harder to "see" God here are lifted away.
Once that happens, we will know very clearly the measure of how we have lived and loved.
It is better to start on the project of being loving through intention and action "here", than spend our lives doing something else, or even the opposite, and then start out "there" having wasted a lifetime.