I'm not sure He actually bled, because the bible says His sweat was AS IT WERE great drops of blood. He could have bled because of the intensity of His prayer, but I believe His sweat represented blood, but wasn't actual blood. The reason I say this is because in 1 Peter 5:8 it says Satan walks about AS A roaring lion; it doesn't say he is a roaring lion, but is like one. Same with the sweat; it is as it were great drops of blood; it didn't say it was great drops of blood. either way, it symbolizes the intense prayer and struggle Jesus was having with both His flesh and going to the cross. In spirit, Jesus was already crucified in the garden before He went to the cross. He settled it before God before they came and arrested Him. That is Hebrews 11:1 in action. As Revelation and Jesus say; those who have ears to hear, let them hear. The rest will just wonder.