There are some profound differences in the ways people understand the significance of Easter, a fact which also applies to Pentecost. Our Lutheran and historical forefathers rightly saw Easter as the celebration of Christ's fleshly resurrection. We do not merely rejoice in an empty tomb. An empty tomb could mean anything; in fact, the first to discover that the tomb was empty were horrified because they thought someone had stolen Jesus' body. It wasn't until they saw Him and became convinced that it was truly He, in the flesh, resurrected, that they were comforted and began to rejoice. Therefore you won't hear the words 'rejoicing at the empty tomb' rolling off your pastor's tongue. Rather, we rejoice with Thomas and all the Apostles who were convinced that Jesus stood bodily before them and said, "Peace be unto you."
So also at Pentecost, we do not merely rejoice in the coming of the Holy Ghost weakly defined in a nebulous or ethereal way at best, or at worst as a reason to go off speaking in tongues and claiming divine intervention. Rather, we see this too in fleshly terms. The Holy Ghost came to the eleven apostles, and immediately they began to preach Christ in several languages. Thus the coming of the Holy Ghost is the coming of the Apostolic Ministry. The Holy Ghost came to Ephesus, to Corinth, to Rome, or to Spain precisely when and in that the Holy Apostles arrived there.
In all this we see the inseparable link between Jesus and the Holy Ghost. In the Western Christian Church we confess that the Holy Ghost proceeds from the Father and the Son, even as we note that the breath of Christ proceeded out of His mouth when He ordained His apostles. St. John's account of their ordination reports that "He breathed on them and said unto them, 'Receive ye the Holy Ghost.'" In English, ghost (or spirit), and breath are separate words, but not in Greek. The word pneuma means both. Pneumonia is a disease of the breath, and pneumatology is the study of the Holy Spirit. Bearing this in mind while considering the passage from the Gospel, we may learn that Jesus' breath and Jesus' Spirit are in fact the same thing. The air that proceeded forth from His very human lungs is, in this case, at the same time very divine; it is Jesus' breath, His Spirit. It was by this breath that He made His disciples into apostles, literally "sent ones." This is all a mystery which therefore we cannot fully explain nor understand, but at least we can say that there is an essential linkage seen here between the Son of God and the Spirit of God.
So also therefore, there is an essential linkage between Easter and Pentecost. Easter is the celebration of the Son in His fleshly resurrected exaltation; Pentecost is the celebration of the Son's sending of the Spirit, in His fleshly ambassadors, His apostles.
Thus in the Christian Church we rejoice during Eastertide particularly over the renewal of Jesus' flesh, His body, upon which we feast; and at Pentecost we rejoice particularly over Jesus' sending of His preachers whose task it is to proclaim Him and His mercy.