Why did the disciples struggle to believe Jesus was resurrected?
They struggled because Jesus appeared so changed from their last view of Him. Scripture implies He was more disfigured and marred on the cross than any human, hardly appearing human, yet now He stood before them seemingly whole except for the wounds. They also believed not for joy and wondered, needing further physical proof.
Les explains that after the resurrection, Jesus showed the disciples His hands and feet to prove He was not a ghost or a mist. He was standing visibly and physically before them, telling them to see the nail prints and check His feet. Yet they still could not believe it was really the same Jesus they had known a few days before; Luke says they believed not for joy and wondered. Les suggests one reason was their last view of Christ on the cross. Isaiah implies He was more disfigured than any human being had ever been, so marred that He did not even appear human. Now He stood before them seemingly whole, except for the wounds. To give proof positive, Jesus asked if they had any food.
And while they yet believed not for joy, and wondered, he said unto them, Have ye here any meat?