Ok, so traditionally we say “a statement that is consistent, correspondent, and coherent.”
But that’s not really clear enough. So, I’ll expand it fully:
1 – categorically consistent
2 – internally consistent (logical)
3 – externally correspondent (empirical)
4 – existentially possible (operationally stated)
5 – rational and reciprocal (voluntary, ethical and moral)
6 – with stated limits and full accounting. (complete)
7 – and coherent across all of the above. (coherent)
The reason being that (a) those are the categories actionable by man) and (b) no category is closed without appeal to the next. and so (c) any statement must pass all those tests.
Now, a fact consists of a theory of a measurement.
And a statement consist of a promise of constant relations.
And a theory consists of a contingent description of causal relations.
You only know falsehoods. We never know truths without perfect knowledge. We never have perfect knowledge. So all we can do is warranty our truthfulness (due diligence) against falsehood.
This is the difference between justificationism (i think this because of these excuses) and falsificationism (i think this because I have no other choice that survives falsification).