Everyone wants various things in life and to get them we must usually take them from others. Morality should be based on a calculation of benefits and harms so that we can get what we desire without antagonizing others in the process.

There will never be a state of perfection in this world. We can, however, seek out challenges and hardships and apply our reason and ingenuity to overcome them. We can't be perfect but we can be just a little bit better every day.

Because accepting any claim and denying the facts leads to religion and the denial of known reality. And history has shown us the destructive and dangerous power of religion.