If this were the year 200 or 300 A.D., we would, right now, be in the middle of the feast of Pentecost.

In modern times (and actually since the late fourth century) we have tagged Pentecost as the 50th day after Easter. For our ancient ancestors the feast included all 50 days after Easter. Both Easter and Pentecost were holidays of tremendous magnitude for the early Christians, and they were deeply related. We should feel their force all the more today.

We cannot, however, until we recover the deepest truths of the feasts.

These are, after all, the only feasts that Christians have carried over from the Jewish calendar — the only annual observances the apostles retained from the years of their religious upbringing and the years of Jesus’ ministry. The Jews of the first century, like the Chosen People in every age, kept Passover as the memorial of their liberation from slavery in Egypt. There were three feasts that all Jewish males were required by law to celebrate in the city of Jerusalem: Passover, Pentecost and Sukkot — and the greatest of the three was Passover. As the modern rabbi Hayyim Schauss put it: Passover is not just a feast; it is the feast.

Yet Passover pointed beyond itself. God liberated his people from slavery so that they could know a better life; and he revealed the character of such a life when he gave Israel the Law. Pentecost was, for the Jews in Jesus’ time, the feast that marked the giving of the Law.

It was at Passover that Jesus suffered and rose from the dead. And so Christians have always observed the event and kept its original, Jewish name. In most places on earth and in most languages — from Albanian to Zulu — the feast is still called by some variant of the Hebrew Pesach. Spanish speakers call it Pascua; Italians call it Pasqua; Greeks call it Pascha. Among the few languages that diverge from this rule are English, German and Polish. The Catechism of the Catholic Church refers to Easter as “the Christian Passover.”

It was the first feast the Church celebrated annually. And for Christians as for Jews, it was the feast. But, again, it was oriented to something else. As the Jewish liberation anticipated the giving of the Law, the Christian liberation (from sin and death) anticipated the giving of the Spirit.

It was at the Jewish feast of Pentecost, the 50th day after Passover, that God sent the Holy Spirit upon the Church. This was the reason for Jesus’ suffering, dying and rising. He liberated us from sin and death — he saved us — so that we might share his life. He rose from the dead in order to make us, by means of the Easter sacraments, “partakers of the divine nature” (2 Peter 1:4).

Thus these two Jewish feasts became foundational dates on the Christian calendar.

In those early centuries, the Church received its new converts in the period stretching from Easter Vigil to Pentecost. Most were adults who came from a pagan background. In the weeks leading up to Easter, they were taught the basics of the Gospel story and the expectations of Christian moral life. Only after Easter were they permitted to know about the sacraments.

The entire Church observed this blackout on information about baptism and Eucharist. Today we call it the “Discipline of the Secret.” The idea was that unbaptized people could not understand the reality of the life of grace, or the Real Presence of Jesus in the sacred host, or the power conveyed by holy chrism. Only once they had received the sacraments would they possess the grace needed to understand them.

The Church, then, spent the 50 days after Easter illuminating these deep matters of faith. They called this period, in Greek and Latin, mystagogia — the “teaching about the mysteries.”

The doctrine of the sacraments arrived as Good News indeed. A pilgrim in fourth-century Jerusalem reported that she saw a crowd of new converts erupting into applause, repeatedly, as their bishop revealed these “secrets” of Christian life.

The Church still refers to this period after Easter as the “mystagogy” phase of RCIA, the time when new converts come to understand the life-changing events they have just undergone.

The great bishops of the early Church saw themselves as following the example of Jesus. They knew that he remained with his disciples for “forty days … speaking of the kingdom of God” (Acts 1:3). Yet the Scriptures tell us not a single detail about Jesus’ curriculum during those days! This was, the early Christians believed, the clear precedent for the Church’s silence about the mysteries.

Preaching in the fifth century, Pope St. Leo the Great said that the days between Easter and Pentecost were God’s favored time for revealing the holy mysteries. “The Lord lingered bodily during this prolonged time so that our faith in the resurrection might be strengthened by needed evidence.”

It was us he taught in the apostles. He anticipated that his chosen men would teach successors, who would teach successors, who would teach successors … who would one day teach you and me. “It was we ourselves who in these men were taught how to meet the objections of the ungodly and the arguments of earthly wisdom. We are instructed by their seeing. Their hearing taught us.”

Why did the Church shroud the sacraments in secrecy? The early Christians gave several reasons. Some mysteries are so great, they said, that they should not be profaned by many words. Some matters are so intimate — like the relations of husband and wife — that they are not suitable for public conversation.

The Church, moreover, learned the hard way not to expose itself to ridicule by pagans who could not understand the mysteries. Among the earliest charges against Christians was that they practiced paganism, eating the flesh of Jesus and drinking his blood. Such urban legends led to real persecutions and martyrdom.

The best witness to eucharistic faith, in any event, was not a lot of talk, but a pervasive culture of Christian charity. It was Christian kindness that first made pagan Greeks and Romans want to seek the source of such love. “See those Christians,” they said, “how they love one another!”

What some pagans sought, they found as Christians. They found it at the baptismal font and at the altar, as we still do today.

Between Easter and Pentecost they learned the truth of what they had been given, and they could not contain their applause. 

Mike Aquilina is co-author, with Scott Hahn, of “Living the Mysteries” (Our Sunday Visitor), a collection of the mystagogical teachings of the early Church. He is also author of “Ministers and Martyrs: The Ultimate Catholic Guide to the Apostolic Age” (Sophia Institute Press).