What did they see that led them to say that jesus lives again?

They saw the guy that they'd been walking around and hanging out with for at least three years, who had been arrested in front of them and then taken outside the city and hanged on a cross, where he died and was stabbed in the chest with a spear till blood and water flowed out, and who was declared dead by a Roman soldier, and buried - they saw that same guy breathing, and talking and walking and eating. And they saw the scars in his body from the crucifixion so they knew he wasn't a ringer. And they touched him; they laid hands on him, so they knew he wasn't a 'spirit.' That's why they said, and still say to this day, that Jesus lives again.