If Jesus had never risen from the dead, then
He must have lied about rising from the dead on the third day.
How would we know everything he said was true?
How would we know we are forgiven?
How would the Apostles have been able to preach the Gospel?
How would we know about the Resurrection of the dead?
But aside from all of that,
Our High Priest and King would be dead. :eek:
The Resurrection is as crucial to the completion of the Sacrifice on the Cross as the Holy Eucharist on that first Holy Thursday was to beginning of the Sacrifice.
Everything in our Faith is built upon the Resurrection of Jesus from the dead.
There are many textbook answers to this question, but the most effective personal answers will be those that come from the Holy Spirit when meditating on the Resurrection.
You must pray the Glorious Mysteries of the Rosary for guidance.