The Paschal season of the Church is preceded by the season of Great Lent, which is also preceded by its own liturgical preparation. The first sign of the approach of Great Lent comes five Sundays before its beginning. On this Sunday (according to the Slavic Lectionary and sometimes according to the Greek Lectionary for which it is the Thirtieth Sunday After Pentecost), the Gospel reading is about Zacchaeus the tax-collector. It tells how Christ brought salvation to the sinful man, and how his life was changed simply because he "sought to see who Jesus was" (Luke 19:3). The desire and effort to see Jesus begins the entire movement through Lent towards Pascha. It is the first movement of salvation.
Our lenten journey begins with a recognition of our own sinfulness, just as Zacchaeus recognized his. He promised to make restitution by giving half of his wealth to the poor, and by paying to those he had falsely accused four times as much as they had lost. In this, he went beyond the requirements of the Law (Ex. 22:3-12).
The example of Zacchaeus teaches us that we should turn away from our sins, and atone for them. The real proof of our sorrow and repentance is not just a verbal apology, but when we correct ourselves and try to make amends for the consequences of our evil actions.
We are also assured of God's mercy and compassion by Christ's words to Zacchaeus, "Today salvation is come to this house" (Luke 19:9). After the Great Doxology at Sunday Matins (when the Tone of the week is Tone 1, 3, 5, 7) we sing the Dismissal Hymn of the Resurrection "Today salvation has come to the world," which echoes the Lord's words to Zacchaeus.
Zacchaeus was short, so he climbed a tree in order to see the Lord. All of us have sinned and come short of the glory of God (Rom. 3:23). We are also short in our spiritual stature, therefore we must climb the ladder of the virtues. In other words, we must prepare for spiritual effort and growth.
Saint Zacchaeus is primarily commemorated on April 20.