Using the Microsoft search engine in Bing, searching on “Bible pentecost” we find the first reference to Pentecost in the religion of the Living God, in the Old Testament. “Pentecost is found in Old Testament Scripture as a Jewish holiday. Pentecost was a Jewish festival that happened during the Feast of First Fruits. Happening 50 days after Passover, which celebrated Israel’s deliverance from Egypt. Pentecost was a time to celebrate the initial harvest feast.” (Exodus 34:22 refers to the Feast of First Fruits). Jews called this feast Shavuot.
Pentecost as celebrated “In the early church, Christians often referred to the entire 50-day period beginning with Easter as Pentecost. Baptism was administered both at the beginning (Easter) and end (the day of Pentecost) of the Paschal season. Eventually, Pentecost became a more popular time for baptism than Easter in northern Europe, and in England the feast was commonly called White Sunday (Whitsunday) for the special white garments worn by the newly baptized. In The First Prayer Book of Edward VI (1549), the feast was officially called Whitsunday, and this name has continued in Anglican churches. In Catholic and other Western churches, priests often wear red vestments during Pentecost to symbolize the “tongues of fire” that descended on the disciples from the Holy Spirit; members of the congregation also wear red in some traditions, and the altar is commonly dressed in a red frontal cloth.” (this quote is from the online Encylopaedia Britannica).
Pentecost is thought of as the birthday of the Church. On Good Friday Jesus Christ offered himself up on the cross as a sacrifice for the atonement of Adams sin. Christ left confession to us in the Catholic Church as a way to have sins forgiven by Christ’s special appointed representatives – priests and bishops, taking the power of forgiveness from the infinite efficacy of his sacrifice of death on the cross. Through his same infinitely efficacious sacrifice on the cross He also gives His specially appointed representatives the power to bring Him back body, blood, soul and divinity in the Eucharist, so that He could actually walk, in person, with each of his followers, until the end of time, individually and personally to guide each of them, through their hearts, back to their home in heaven.
Pentecost marks the completion of the process which Jesus Christ, the Second Person of the blessed Trinity, used to redeem mankind. It started with His sacrifice on Good Friday to atone for the Sin of Adam and Eve individually and as a society (remember Eve convinced Adam to eat the fruit of the knowledge of good and evil) as well as every man or woman through out time that took advantage of joining His Church/religion and taking advantage of the efficacy of His redeeming sacrifice through sorrow/contrition for their sins and performing the penance given by Jesus Christ’s specially appointed representatives to have their sins forgiven. This was to bring mankind into understanding God, as much as he could at the emotional level, specifically his love for mankind.
Though I am sure Jesus Christ’s sacrifice was accepted when he breath his last on the cross, for mankind to receive the full efficacy of it, they had to absorb the second part of the process of redemption, the resurrection on Easter day. The women came to the tomb easter Sunday, basically to honor and give their condolences to the great teacher of unconditional love (charity) and healing only to find the stone covering the tomb rolled away and the “body” (no longer dead but resurrected through Jesus Christ’s own power as God the Son) was missing with a young man in the tomb announcing he was risen (Matthew 28:6). The resurrection gave credence to his claim that He was God and gave future saints like the 12-year-old Saint Agnes who was tortured to death i.e. martyred, that God loved them enough to die a most agonizing death and show us, in the flesh that there was life after death, as he preached. It gave the martyrs the confidence that if Christ did this for us, creatures created out of nothing, how much better must be his promise of indescribable happiness after death if we but be his steadfast disciples (2 Corinthians 2:9).
In addition to this part of the process was to appear to some “critical mass” of people who could be witnesses of His resurrection and so he could clear up some questionable things in the Old Testament in general and things concerning him in the Old Testament and also presumably somethings that might be confusing in His preaching during his active ministry (Luke 24:13-47). This was to bring mankind into understanding God, as much as he could at mental level, specifically that God planned from the fall of Adam and Eve, to save mankind and man’s salvation was the goal of history and God’s love.
The second to last or third part of this process was Jesus Christ’s Ascension. His rising to heaven indicated that his sacrifice on the cross was accepted by God the father, as smoke rising from a burnt offering, in previous times indicated God’s acceptance of a sacrifice. This was to bring mankind into understanding God, at the physical level, that He was in charge of everything physical and that Christ rising to heaven, against the known laws of gravity (as was seem in psalms 107:29 and the calming of the seas in Luke 8:22-25) was truly God, master of all nature, and able, in an unlimited way, because of his love for us, to help us whenever we might be in trouble, not only mentally and emotionally but physically. The final part of the process was Pentecost, when He sent the Holy Ghost to help us, because of his love, in a spiritual way, until the end of time. God the father helped mankind through the Jewish people and prepared the world for His Son which was shown in the Old Testament. God the Son showed humankind by living example how to live in the New Testament. Finally, God the Holy Ghost will guide mankind until the end of time how to apply Jesus Christ’s example.
Traditional Thomistic Catholic 