I don't have a problem with anyone's belief in spontaneous generation. I just don't believe it. I don't believe it because there are no examples of a living thing, simple or complex, coming forth from non-living matter and there is no one claiming to have observed it.
The difference is that there are, as you say, plenty of people who claim to have experienced god but they have absolutely no evidence whereas scientists researching the field of abiogenesis have some evidence of the necessary precursor stages - such as the formation of RNA.
If someone believes that living things do, or have, come forth from non-living things, no problem here but it is simply a belief that person holds on faith. It is similar to a religious belief. It is held as truth even though it cannot be proven.
See above. There is some evidence pointing to possible mechanisms for abiogenesis, research is continuing and is likely to produce more evidence. There is no evidence for the existence of gods and none is likely to be forthcoming. You have faith, which is belief in the absence of evidence, but abiogenesis has some hypotheses backed by evidence.
One difference between belief in God and belief in spontaneous generation is that no one claims to have observed spontaneous generation, while billions of people from all societies, time periods, education, and socio-economic levels claim to have experienced the presence of God.
Apart from being a logical fallacy, argument from majority, this ignores the fact that many of those people's experiences will be of different gods to that which you believe in. Which of those gods is correct and why?
science is observable and reproducible and spontaneous generation has never been observed nor reproduced.
Prior to July 1969 man hadn't walked on the moon, science and engineering made that possible. Prior to earlier this year whole, living, fertile mice hadn't been produced from mouse skin cells, science made that possible.
Although there's no evidence that he ever actually said it, the misquote of Charles Duell, head of the US Patent Office in 1899, that "Everything that can be invented has been invented" seems appropriate. Do you think, misquote or not, that anyone can reasonably ever make that claim?
Just because abiogenesis hasn't yet been reproduced in the laboratory it doesn't mean it never will be, especially considering the extent of existing research. This is quite unlike a belief in god.