The building blocks of life can, and did, spontaneously assemble under the right conditions. That’s called spontaneous generation, or abiogenesis. Of course, many of the details remain hidden to us, and we just don’t know exactly how it all happened.
Or how frequently it could happen.
The world’s religions have different ideas of how life appeared, of course, and they invoke the magical hands of various supernatural deities to explain it all. But those explanations, while colorful tales, leave many of us unsatisfied.