What evidence supports that he is?
I really dislike this argument about religion and the "burden of proof". The other side will say something about proof, when such a thing can never be proved nor disproven, at least not yet.
I do find it to be somewhat fascinating that there are so many diverse viewpoints here.
Depends there's a fair amount of evidence. A singular post isn't going to encapsulate everything but I will do my best to include a cursory amount of evidence. This will also Ignore logical arguments for it such as the Kalam, Teleological, morality, etc.. The logical arguments get to "God" existing but not necessairly the Christian God. I have written about this before and most of this is ripped and changed a little to make it into a post for here. So if something seems off that is why...
Historians almost universally agree a man named Jesus existed and was crucified. Want some evidence of this. Justin the Martyr 110-165 in his writings attests to seeing Jesus birth and death certificate "25 stadia from Jerusalem". Notably he wasn't brought up particularly religiously. His father was suspected of being a pagan for instance and he was born in Palestine.... In case his name didn't give it away he was beheaded for his beliefs. In terms of eyewitness testimony by a non-Jew or at the time Christian this is gold. It attests to the life of Jesus.
Jesus saying he was God.... For the sake of keeping this as short as possible he said so in numerous bible verses for instance John 8 58, John 20:28. Matthew 14:33, John 10:30..... It is very clear Jesus called himself God. That doesn't make you God. There must be further proof. Something like a painful death and coming back alive perhaps?
Is there proof of the resurrection?
Notably even JAMA has an article published as a "case study" where they say Jesus died on the cross.
The disciples were eyewitnesses to the events. In order to understand the crucifixion we need to understand the events therein and surrounding.
He entered the garden of Gethesemane where he experienced a bout of hemohidrosis in other words colloquially he started sweating blood. Hemohidrosis doesn't result in significant blood loss but what it does is make the skin very fragile which is salient for what follows. What happens if you are curious is the capillaries burst under extreme stress into the sweat glands... Skipping ahead during his "trial" he was sentenced to severe flogging on his already fragile skin. While the number of strikes isn't recorded customarily it was 39. Also saliently a large majority of people died as a result of these floggings alone. The flogging instrument was called a flagrum which was composed of bone and metal attached to leather. Designed for damaging and ripping skin. Blood loss would be massive.
Roman's were not scourged instead they were more beaten with sticks. This is actually dictated in the bible when Paul objects to being scourged. Why was this the case because it seen as a slave punishment. It was deeply feared. Flavious Josephus in his writings mentions scourgings in Palestine that exposed the persons innards. Also whilst there was a limit (40) for Jews being beaten there was no such rule for Jesus as this was dictated under Roman law. Meaning an infinite amount of strikes could be levied. The word used in Greek to denote it was Flaggellum or the word specifically denoting scourging. Other words could be used denoting lesser flogging. Also saliently it is mentioned in Mark that after this they repeatedly struck him in the face after placing the crown of thorns on his head. A) digging it deeper B) Causing further bleeding In Mark 20 we find out his robe was torn off his back. So his back that has sustained a scourging suddenly has fabric ripped off of it. Other than the fact the pain must have been blinding it would also reopen any clotted wounds. None of that sounds to me like he escaped with minimal blood loss. As mentioned it is just a widely known historical fact that roman floggings frequently ended in death due to blood loss. This was also done to appease the raucous crowd. Do you really think they are going to go easy on him? Not a chance. Again their own ass would be on the line if it wasn't done satisfactorily.
Additionally, during the trial he had a crown of thorns with thorns customarily an inch or two long pressed into the skin of the entire scalp. Thus, causing even further bleeding. In Isaiah we find a foretelling of the beating saying " Just as there were many who were appalled at him -- his appearance was so disfigured beyond that of any man and his form marred beyond human likeness--" and "I offered my back to those who beat me, my cheeks to those who pulled out my beard; I did not hide my face from mocking and spitting.".
Jesus still alive was forced to carry his own execution implement his cross which weighs between 80 and 110 pounds. He fell and collapsed at some point likely due to blood loss. Some have theorized that he fell down the stairs and sustained a heart contusion. The crucifixion itself involved nails, about 7 inches long and with a diameter of 1 cm ( roughly 3/8 of an inch) were driven in the wrists. The points would go into the vicinity of the median nerve, causing shocks of pain to radiate through the arms. It was possible to place the nails between the bones so that no fractures (or broken bones) occurred. Studies have shown that nails were probably driven through the small bones of the wrist, since nails in the palms of the hand would not support the weight of a body. The feet were then nailed to the stipes. To allow for this, the knees had to be bent and rotated laterally, being left in a very uncomfortable position. The titulus was hung above the victim's head. Having suffered from the beatings and flogging, Jesus suffered from severe hypovolemia from the loss of blood. The verses below describes His dehydrated state and loss of His strength."I am poured out like water, and all my bones are out of joint. My heart has turned to wax; it has melted away within me. My strength is dried up like a potsherd, and my tongue sticks to the roof of my mouth; you lay me in the dust of death."When the cross was erected upright, there was tremendous strain put on the wrists, arms and shoulders, resulting in a dislocation of the shoulder and elbow joints.(Metherall) The arms, being held up and outward, held the rib cage in a fixed end inspiratory position which made it extremely difficult to exhale, and impossible to take a full breath. The victim would only be able to take very shallow breaths.(This may explain why Jesus made very short statements while on the cross). As time passed, the muscles, from the loss of blood, lack of oxygen and the fixed position of the body, would undergo severe cramps and spasmodic contractions. But don't worry we also know on the cross to breathe he would have to throw his back against the cross and literally scrape his mutilated back up to elevate his ribs to exhale. Again this would serve to reopen the wounds every time.
We also have a spear thrust into Jesus side John 19:34. Wherein blood and water rushed out. The water is a massive sign that he was in fact dead. Also the reason they pierced his side is also incredibly salient. They came to break his legs as was custom to expediate the death on the cross. Why does this expediate it? Because breathing in the bodily position on the cross required activation of the legs to drive your torso up so your lungs could expand. If your legs are broken you won't be able to elevate your ribs and expand your lungs. Notably they broke the legs of the other two people hanging on the cross with him *before* Jesus. Once they got to Jesus they realized he was dead. Now all the discussion in the bible for this occurs Jesus has passed and given up the "ghost". Why is this salient because how long can you hold your breath 2-3 minutes? In order for you to make an argument he wasn't dead at this juncture You would have to say Jesus to have held his breath for potentially hours....
The soldiers chosen to kill Jesus were the best of the best. These were the navy seals, green berets, rangers, etc.. of the day. They were very very good they knew how to kill and they didn't make mistakes. Their lives were on the line if they made a mistakes.
He had armed guards around his tomb round the clock. He was first seen 3 days later. So Jesus who had sustained massive trauma/blood loss, a punctured lung, most likely a punctured heart, had barely drank any fluids in the hours on the cross (a vinegar wine-which would dehydrate you). By the way not sure if you are aware of this but he would be in the desert. So he would be insanely dehydrated. If you say he somehow survives all of this he does so without fluids or medical intervention wrapped in traditional burial clothes in a tomb. If he would manage to survive all of that and appear 3 days later I contend it would be a bigger miracle then if he is God and was risen from the dead.
Following this we know that Jesus appeared to ~500 people and these things were written about etc. in the towns these people lived in.. Now not only is there no benefit for them to lie. What is the benefit for Jesus and his followers to lie. His disciples also willing had painful deaths. I could continue but I will let you refute the above because this is already quite lengthy. I can get into the evidence following his death then if you wish. Such as how we already have ~500 eyewitnesses, there's early texts from as early as 15 years following his death. Within 200 years I believe the entire bible with the exception of a few verses can be completely made using references despite the events of the time etc...
Other cases of crucifixion and surviving?
Actually yes in Josephus' writings... We have 3 people where the crucifixion was intended to be *lethal* but was ***interrupted***. "I saw many captives crucified, and remembered three of them as my former acquaintance. I was very sorry at this in my mind, and went with tears in my eyes to Titus, and told him of them; so he immediately commanded them to be taken down, and to have the greatest care taken of them, in order to their recovery; yet two of them died under the physician's hands, while the third recovered." Meaning even in the best situation people will die. I don't recall the exact nature of their crucifixion off hand but I do believe it was only a few hours and flogging wasn't mentioned. Simply put Jesus claimed he was God, performed miracles, was crucified in arguably one of the most execution methods in human history, and rose from the dead.
Lastly, we have manuscripts from as early as 10-15 years post death which is unheard of for ancient documents written in the place and period of people who witnessed these events. There is also more ancient manuscripts for Christianity then any other ancient event, person, etc... See here ->
https://www.thecollegechurch.org/wp-content/uploads/2016/08/HANDOUTS-Is-Scripture-Reliable.pdf or here ->
https://biblequestions.info/2019/12...scripts-compare-to-other-ancient-manuscripts/ . Meaning in terms of reliability the bible my be the most accurate text we have. ~30,000 manuscripts to for instance Caesars 250 or so for the gaelic wars.