the courts of law use eye witness testimony to sentence people to death. even if it is jsut one good eye witness, it might be enough. depends on the jury.
That's becoming increasingly rare. And rightly so, because it's really, really stupid. There's no such thing as a "good eyewitness". If you don't believe me, watch this video. It's a card trick in which the magician changes the backs of the deck of cards from one color to another one. Watch very closely, and see whether you can catch the trick after they reveal it. Almost no one ever does. (I didn't, either.)
when Jesus rose from the dead, multitudes saw Him. 100's of people in crowds all together interacted with him. Thomas put his fingers through the holes in Jesus' hand.
I find it very annoying that so many people in scripture got direct confirmation of their god's existence, but I'm supposed to decide the fate of my eternal soul on a 2,000-yer-old book whose authorship is largely anonymous and whose events are almost entirely uncorroborated (and, in many cases, demonstrably false). At best, all this demonstrates is that if Yahweh exists, he is not a just being.