The Bible is full of stories, some symbolic, some metaphorical, and some in parables, so too there is the story of Jesus the Christ. In order to understand the Messiah, it is important, of vital importance, to comprehend and to understand that Christianity would not exist, without the resurrection, without the ascension of the Christ, and without the Pentecost, because without these events you have a man of great wisdom, a great prophet, and a great mentor, but you do not have the immortal Christ.
While there isn’t anything necessarily wrong with presentations of Jesus that ends with His death, because physical death is almost invariably the lot of humanity, believing this though in such a manner, that Christ died on the Cross, never to return is foundationally wrong, and isn't consistent with Biblical truth, or the life of the Christ. Those that somehow can't accept the concept that anyone could ever come back from physical death in any form, aren't Christians in the most complete sense of word, but rather are those that are essentially reduced to the admiration of a good man, a prophet, and a wise soul. On the other hand, in order to be considered a Christian, you have to implicitly believe that Christ rose from the dead on the third day, that he thereby consorted with his apostles, later to ascend to the Father on the fortieth day, followed by the Pentecost of the Holy Spirit that descended upon the apostles on the fiftieth day of Jesus' death by crucifixion.
The thing is, the apostles that went forth to preach the Word, did not do so, under the impression that they were preaching about a good man, or simply a prophet, or remembering the wisdom of a wise soul, they were instead specifically preaching that Jesus the Christ, was crucified, that He died, andthat on the third day, Christ rose again as He reconstituted his body, still containing the wounds of his crucifixion, and walked, preached, and mentored his apostles, before ascending to the Heavens, from which he originated in spiritual form, and on the fiftieth day the Holy Spirit descended upon the apostles, which created a unity of spirit, through the "tongues of fire" which rested upon each of them.
The apostles of Jesus now well understood, that the man that they had been listening to, learning from, and walking with, was not just another great prophet from God, was not just a spiritual man who could heal people from injuries both psychological and physical, was not just a man gifted with the ability to raise the dead back to life, but that He was the son of man, that is physically present here on earth, as well as through his spiritual oneness with God, the son of God. This meant, that the Christ the apostles preached and ultimately the Christ that they proselytized about, was the immortal, unchangeable, omniscient, Creator God of the universe, the alpha and the omega. It was their firm belief in the knowledge that Christ rose from the dead that inspired these good and common salt-of-the-earth men, to preach boldly, knowing that in time that they too would become martyred but that their deeds would live on in the generations to come.
The story of the Christ is not and cannot be complete without the story of His Resurrection and ascension, demonstrating conclusively that fallen man suffers from the illusion that mortality is the end, whereas instead all that we are is actually contained within our indestructible soul which cannot rest till it rests within the heart of God.