And the disciples had both.
They had the miracles, the teaching, the empty tomb, they saw and observed the physical evidence.
They also had the physical, resurrected, living Jesus appear to them and allow them to touch Him and put their hands in His wounds. You can’t get much more proof than that.
The apostles... Yes, they were blessed with a lot more evidence (proof, if you wish) than the rest of us were, but I suspect that they were given that proof because they already had faith.