"(scientific fact) an observation that has been confirmed repeatedly and is accepted as true (although its truth is never final).
This has never been the case with Evolution, One Species has never been observed to evolve into a New/Different Species. The atheist will likely reply with the fact that Micro-Evolution has been observed, but this is not proof, How so?
All it proves is that a Species can improve and adapt to it's environment, Not evolve into a New Species.
Unless One Species is Observed and Repeatedly Confirmed to Evolve into a New/Different Species, Evolution is not a Fact, not even a Theory, as no Evidence has been found for it.
So when an atheist tells you that Evolution is a (Scientific)Fact, you ask, "Has One Species been observed to Evolve into a New/Different Species?"
if they reply with Micro-evolution, you tell that person, "This proves one species can adapt to it's environment, and stays the same species, this is not Observation of One Species Evolving into a New/Different Species"
If they reply saying, "It takes millions/billions of years, we can't observe it"
you say, "Then Macro-evolution will never be a Scientific Fact and one cannot ever say Evolution is a (Scientific)Fact"
When someone says that Evolution is a fact they either may be lying, lack knowledge of science or deceived.