Many did not believe when Jesus told them He would be resurrected on the third day, but they were amazed when they heard Jesus talk about this event, they doubted Him, they did not believe.
The same happens in this time and perhaps worse, people only look for Jesus when they have a problem, and after God helps them with their problem, they return to what they were before.
Jesus said to her, I am the resurrection and the life. He who believes in Me, though he may die, he shall live.
This people with whom Jesus worked day after day, did not believe that He could raise the dead, even seeing the signs and miracles that He did before their eyes. Reading the Gospels we will find several miracles that Jesus did during His journey through those cities.
But what those people did not know was that Jesus was speaking of an eternal resurrection, which would be received by those who believed in Him, as the following biblical verse says, that whoever believes in Him, even though he is dead, will live.
And whoever lives and believes in Me shall never die. Do you believe this?
This is a great truth, He is the life, only in Him we must believe, because there is no other in which we can be raised, and this is why we must believe fully in Jesus, He is the life, and we will die, but not eternally, because God will raise us in the day of His coming, and we must believe in this great promise made by Him.
She said to Him, “Yes, Lord, I believe that You are the Christ, the Son of God, who is to come into the world.”
This is Jesus whom we must believe all the time, as one of His disciples named Peter have said, affirming that Jesus has come into the world to give us salvation and eternal life. Remember that to achieve salvation and eternal life you must believe in Him.