"These things are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name" (John 20:31).
Which events of Jesus' life do you think were insignificant? Which of the things he said or did is not worth taking notice of, or remembering, or examining? As soon as we ask the question, the answer becomes obvious: if God considered any event of Jesus' life worth recording for us, he must consider that event to be important for us.
The life of Jesus has the power to save us. The events that make up his life—what he said and what he did (Acts 1:1)—can be used to lead us to belief and faith that results in salvation. As we immerse ourselves in them they can strengthen our conviction (Luke 1:4) and establish us in the truth (2 Peter 1:8, 12).
Every recorded event of Jesus' life has lessons for us. The events of Jesus' life are recorded for us to remember, study, re-enact, commemorate and meditate upon. By regularly doing this—for instance, by an annual cycle that keeps returning us to events in the life of Jesus Christ—we grow in faith, we draw closer to the heart of God and we are increasingly equipped to produce fruit for our Lord.
The events of Jesus' life exercise their power in our lives only to the degree that we remember them. We are called to do more than just read about them or study them; we are called to experience Jesus' life by celebrating and even re-enacting major events. If events of the past are allowed to remain nothing more than a written record, they lose part of their power. When we turn those past events into ongoing celebrations, lives continue to be transformed.
Ancient Israel's experience teaches us the value of such an annual rehearsal of God's acts of salvation. Every year they rehearsed the great salvation events of their history, the events in which God acted to save them. Their weekly Sabbath and annual festivals were designed to remind them how God had freed them from their slavery in Egypt (Deuteronomy 5:12-15; Exodus 12:11-12, 26-27, 42; 13:3,8-10; Deuteronomy 16:10-12; Leviticus 23:43). By celebrating this way they annually remembered what God had done for them, they renewed and deepened their relationship with God, and they remembered their responsibility to God.
And they were not restricted to worshiping on those days alone. They continued to see the hand of God in their history long after the Exodus, and so they created additional days of worship to remember and celebrate his intervention, power and love. For example, they instituted fasts in the fourth, fifth, seventh and 10th months to remember the destruction of Jerusalem and the temple by Babylon, and the beginning of their exile (Zechariah 7:5; Jeremiah 52:12; 2 Kings 25:8-25; Zechariah 8:19; 2 Kings 25:1; Jeremiah 39:2).
And when God delivered them from persecution by Haman through Esther in the fifth century B.C., they commemorated his deliverance by creating the Feast of Purim (Esther 9:27-28). After God delivered them from the oppression of Antiochus Epiphanes in the second century B.C., they instituted the Feast of Hanukkah, mentioned in John 10:22, as a festival of remembrance and rejoicing.
Like Israel, we Christians have a great salvation-event to remember. Unlike Israel's, ours is not just a salvation event. It is the salvation event: the life, death and resurrection of Jesus Christ by which we are saved from sin and death.
Unlike the old covenant, which God made with the nation of Israel, the new covenant, which he has made with his church, contains no commanded days of worship. Under the new covenant, the church is free to designate days on which to celebrate and re-enact God's act of salvation in Jesus Christ. Those celebrations can draw upon imagery from some of the festivals of Israel, which, while they looked back to that nation's salvation from Egypt, also can remind us of a greater salvation, which has now come in Jesus Christ. Or they can be Christian celebrations at various times of the year, designed to remember and celebrate events of the life of Jesus.
The church is not commanded to adopt worship celebrations for all the events of the Gospels, but it is permitted to adopt as many worship celebrations as it feels appropriate. And the church is free both to reinterpret the festivals of Israel, and to create new festivals, to remember the life of Jesus through whom we have salvation.
Which events in Jesus' life are significant enough to remember? Any and all of them. If an event of his life was significant enough to be recorded in Scripture, it is significant enough for us to remember and to celebrate.