Acts 1:11 They said, “Men of Galilee, why do you stand looking up toward heaven? This Jesus, who has been taken up from you into heaven, will come in the same way as you saw him go into heaven.
When we die we will see Jesus descend just like He ascended into heaven. Glorified and we too will be glorified…We see what that looks like in the transfiguration… From death into life it is a transformation…Revelation 21:5 He who was seated on the throne said, “I am making everything new!” Then he said, “Write this down, for these words are trustworthy and true.”
Well when Jesus breathed on the Apostles, He filled them with the Holy Spirit and sent them out on a mission… That’s what it means to be an apostle… To be sent out… Before the ascension and at the Pentecost with all those gathered.
We see God has breathed the Holy Spirit different times in scripture. When God breathed into Adams nostrils He gave Him life and Adam was in communion with God… When Jesus breathed on the apostles before He ascended into heaven (which we celebrate on Ascension Sunday) Jesus gave them the Holy Spirit anointing them to be priests and sending them out on their mission to spread the faith as priests who were able to baptize, forgive sins, etc. thus building up the Church… When the Holy Spirit came down upon the disciples at the Pentecost it brought life to the Church by anointing it with the HS, and thus in communion with Him… Remember we pray in our profession of faith, I believe in the Holy Spirit, the Lord giver of life?? Well it is the Spirit which gives life. John 6:63 . The Spirit even gave life to Jesus in Mary’s womb… She was conceived by the Holy Spirit…

When we receive the Holy Spirit at our baptism, we start our new life in Christ… All because of the gifts that God gave us of the Holy Spirit.
Breathing the spirit into the Apostles in John 20:19, who were the first priests of the Church, gave them the ability to forgive sins but not all the Church was gathered there… In other words it passed the authority of God for them to absolve sins directly from Jesus Himself, thus completing the work Jesus was sent to earth for so afterwards Jesus ascended back into heaven because He had taught the apostles what they needed to know
and sent them out, anointing them with the Holy Spirit so they had the ability and help doing the things they needed to do in their priestly ministry such as absolving sins, baptizing, marrying, anointing the sick, etc in order to build up the Church and help it increase in numbers… the Holy Spirit wasn’t for them to keep, it was for others as it is now… . When more met in the upper room in the Pentecost later Jesus wasn’t seen in the physical sense (though He was there), and the disciples were greater in number from all nations and gathered together in the upper room. The Holy Spirit came upon them and they began exhibiting the gifts of the Holy Spirit, speaking in tongues, etc., and becoming one with each other in the Spirit of God. So we began a people of One Lord, One Faith, One Baptism, Ephesians 4:4-5 and it officially marked the birth date of the Church. Notice Jesus wasn’t physically present there but yet they were in union with each other bound together by the Holy Spirit with Jesus there but not seen, because He had ascended into heaven ten days prior…Now He sits on His throne at the right hand of God remaining King reigning over all of creation…