It doesn’t require any faith NOT to believe in something. God is not a disprovable concept. Nor, by all the arguments presented for a deity’s existence so far, does it appear all that provable. Regardless, there’s no burden on a non-believer to prove anything. The burden of proof is always on the person asserting the existence of something. You appear to be treating belief and non-belief as two positions with equal burdens in any discussion regarding the existence of a supreme being. They are not.
Furthermore, atheism (or agnosticism) are not frameworks for a worldview. They are not ‘belief systems.’ By definition they represent the absence of a belief in a god(s), with the atheist making a stronger negative assertion while the agnostic dismisses the idea more with a shrug. Indeed, the word agnostic can be applied to anything since it simply means ‘without knowledge.’
Nothing really naturally follows from a lack of a belief in a god. It’s even possible to believe in life after death without believing in the existence of a supreme being. The Buddhist religion is a prime example of a belief system without a deity as such that also holds that consequences will result in the next life from actions we take in this one.