The final gift that God has given us, so far, is the Holy Spirit. This gift "overshadowed" Mary result in the Immaculate Conception, but later appeared after Jesus had gone up to heaven.
In Acts, tongues of fire descended on the apostles, who had been in hiding after the resurrection, waiting to see how the land lay and fearing persecution. The tongues of fire were the Holy Spirit, which not only gave them renewed confidence, but the ability to speak all the languages of a diverse crowd.
Since that day of Pentecost, the Church never looked back. Jesus' followers would take the good news all over the Roman Empire. Many would die for it and did so gladly. After all, it was only death - they would soon be with Jesus.
From a small sect to a global religion; that's what the Holy Spirit caused to happen to Christianity. It still acts in mysterious ways today; including, I would say, in my own life.
There is still one more gift to come; a new Heaven and a New Earth.
With that, I wish all my readers a Merry Christmas and a Happy New Year!