All any of us have on the subject of God is an opinion.
That is absolutely correct.
Since there is nothing of substance that can be measured or evaluated about "god," upon what does one base an
opinion regarding the matter?
The atheist is not "anti-god" in the sense that people are anti-Bush or anti-Obama any more than they are anti-Santa because there is nothing about god (in and of the imagined entity itself) to oppose.
But there is a large contingent of pro-god people. The astounding thing is that they cannot agree amongst themselves even within the same sect of the same religion about this entity. And this is for
the very same reason that the atheist concludes that there is no god; there is no evidence to evaluate. They just simply glom onto some person who is preaching something that is in line with their own opinions and feelings and let that person mold their thinking.
And yet even this evidence does not cause them to pause and think "Why is it that we don't agree? Is it not simply because we don't know? And why don't we know? Is it not because there is no way of knowing because there is no evidence that we can evaluate and all these opinions are simply a reflection of each person's personality and mental processes?" No. You will seldom find that kind of honest evaluation among the religious.
And that is, in a way, understandable. After a lifetime in prison, it is frightening to be released into normal society because the cultures are very different. I have made the transition from a lifetime where religion dominated every aspect of life to one in which I actually have to think for myself and it is terribly hard. I get that. But in the end I much prefer reality to delusion.
It is these same pro-god people who are sometimes anti-human-being in the form of discriminating against certain groups of people and imposing their morality,
which is based on nothing more than an opinion, on the rest of society.
For this reason, it has become necessary for some to stand forth and state the facts that there is no evidence and it
is all based on opinion (as you say) and therefore isn't it more reasonable to conclude that since there is nothing to measure that there is no way to justify the idea that god exists, let alone what he may or may not think or want or command?
When someone claims to be an atheist, the practical upshot is that they are anti-religion, not that they are against god per se. I have yet to meet an atheist who would not readily admit to the existence of god if god ever actually showed up and communicated on a level that humans can understand.