Christ is risen! Truly He is risen!

On this feast, our Lord Jesus Christ appeared for the second time to His disciples after His Resurrection from the dead. The first appearance was in the evening on the same day of His Resurrection (John 20:19). However, Thomas was not with them (John 20:24). So He appeared again this second time on that Sunday to strengthen Thomas' faith (John 20:26).

Our Lord Jesus Christ wanted to establish for us that Sunday is the day of the Resurrection and should be the day that is consecrated for Him. Thus He appeared to Thomas with the rest of the disciples on the Sunday following His Resurrection. This is why the Church chose to make Thomas Sunday a feast and called it the "New Sunday". Sunday is also known as the "day of the Lord" in Greek (Kyriake), Coptic, and Latin (from which the French word for Sunday [dimanche] comes). This was the day when St. John the Evangelist saw the Revelation: "I was in the Spirit on the Lord's day" (Rev 1:10).

Besides the Resurrection of our Lord Jesus Christ from the dead, there are many other events that occurred on Sunday to establish its glory and the day consecrated for Christian worship:

God began His creation of the heavens and the earth by creating the light on the first day. Thus, when our Lord Jesus Christ rose from the dead on the first day of the week, He was showing that He has become the "firstfruits of the resurrection" (1 Cor 15:20). He is also the "Light of the world" (John 9:5; 12:35,46) Who is "the firstborn over all creation" (Col 1:15) and the "Sun of righteousness" Who "shall arise with healing in His wings" (Mal 4:2). For this reason, we read on the Feast of the Resurrection: "This is the day which the Lord has made: let us rejoice and be glad in it. O Lord, save us; O Lord ease our ways... God, the Lord has shined upon us" (Ps 117, LXX). Moreover, all who have been baptized have become a "new creation" (2 Cor 5:17; Gal 6:15) by being buried and risen with Him in the hope of the resurrection of the flesh on the last day.
According to Abba Sawirus, ibn al-Muqaffaa, Bishop of al-Ashmunein (10th century), we have received the tradition that our Lord Jesus Christ was born on a Sunday, and thus, was also circumcised on a Sunday (the 8th day from His birth).
Our Lord Jesus Christ entered Jerusalem as a King on a Sunday.
The Holy Spirit descended on the Church on the day of Pentecost, also a Sunday.

The tradition and practice of the early Church as shown by the Holy Scriptures and the Fathers was to consecrate Sunday as the day of the Lord, the day of worship and gathering for the Eucharist:

"Now on the first day of the week, when the disciples came together to break bread..." (Acts 20:7).
"On the first day of the week let each one of you lay something aside, storing up as he may prosper..." (1 Cor 16:2).
There are also many references to this in the writings of the Fathers such as the Didache, Epistle of Barnabas (ch. 15), St. Ignatius Theophoros, St. Justin Martyr, St. Clement of Alexandria, Origen, St. Athanasius, the Apostolic Constitutions and many others.

An important point to be noted is that Thomas was not there on the Sunday that our Lord said He would appear to His disciples and missed that peace and blessing given to them. Likewise, when we do not come to participate in the Divine Liturgy on Sunday, we lose that peace and blessing granted to us through the communion of the Lord's Body and Blood. Thus, the Church laid down canons punishing those who would miss the worship in the Church on Sunday.

Thus Sunday has become our new Sabbath, our new day of rest, due to the Resurrection of our Lord Jesus Christ from the dead in hope of the resurrection from the dead and the life of the coming age with Him, in the glory of His Father, and in the fellowship of the Holy Spirit. Amen.

Holy Bible Interesting Fact