It is not an assumption as much as it is a practical convenience. No, I repeat, it is a practical approach to investigating the universe. It is methodological naturalism. i.e. we decide we shall only investigate those matters that are likely to have a natural explanation because science is not well suited to investigate matters that occur without regard for the laws of nature. No. Abiogenesis is a descriptive terms that covers a suite of hypotheses to account for the origin of life. Indeed the account of creation in the Bible is one of the hypotheses of abiogenesis. Abiogenesis simply means that life arose from non-life. In Genesis God created man from the dust of the Earth. Correct? That's life from non-life - abiogenesis. If you deny abiogenesis you deny Genesis. If someone declares that they are 100% certain that abiogenesis occurred you might describe it as a faith position, I would call it a silly idea. The correct position on abiogenesis is to note that, based upon current evidence, it seems that one or more chemical processes led, over time, to increasing complexity of autocatalytic chemical cycles that eventually merged into life. The only assumption here is your assumption that you understand what is meant by macroevolution. Assassination is not necessary when an individual commits character suicide through repeated displays of intellectual dishonesty. Shame on you.