Let’s approach this significance by means of a different question. Why did the first Christians choose Sunday as their day of worship? It is a key question with a answer of ultimate importance for Christians.
It would have made sense for the first Christians, deciding that they would worship together once every week, to choose a Thursday as THE day. After all, the Eucharist is the source and summit of human existence. The first Christians knew this, and might have chosen the day of the Last Supper as their “Lord’s Day”. Evening would have been ideal.
But the first Christians did not choose Thursday.
Friday would have been an understandable choice. The suffering and death of Jesus is the heart of our faith. Three o’clock on the afternoon of every Friday might well have become the new sabbath for Christians.
But Friday was not chosen.
Saturday was already the Jewish Sabbath. Jesus came to fulfill all the hopes and promises of the First Testament. Jesus is the fulfillment of the covenant that God made with the Jewish people, the first ‘people of God’. The early Church community could have claimed the existing sabbath by proclaiming Saturday as the day of fulfillment, brought by the saviour.
But the early Christians did not choose Saturday.
Instead they chose Sunday, the day of the resurrection of Jesus. The women went to the tomb at sunrise on the first day of the week, Sunday. They found that the stone had been rolled back from the tomb entrance.
He had risen. And nothing would ever be the same again.
Today, two thousand years after this cosmic event, Christians gather every Sunday to celebrate the Lord’s day as ‘the FIRST DAY.
Until very recently our churches were built to face the rising Sun. Priest and people together worshipped God, facing the rising sun.
And this, because today we celebrate the event when the Son of God rose from the grave, and overcame death that we might live now, and forever.