Today, the Universal Church celebrates the Dedication of the Basilica of St. John Lateran in Rome because it is the head and mother church of all churches in the world.
The fact is that the Basilica of St. John Lateran is the Pope’s cathedral because St. John Lateran's Basilica is the Cathedral of the Diocese of Rome, and the official ecclesiastical seat of the Bishop of Rome, who is the Pope.
The first basilica on the site was built in the 4th century when the Roman emperor Constantine donated land he had received from the wealthy Lateran family.
That structure and its successors suffered fire, earthquake and the ravages of war, but the Lateran remained the Church where popes were consecrated until the popes returned from Avignon in the 14th century, after which they resided in St. Peter's.
The dedication of this Church is a feast for all Roman Catholics because St. John Lateran is the parish church of all Catholics since it is the pope's cathedral.
This church is the spiritual home of the people who belong to the Roman Catholic Church.
In celebrating the dedication of the Pope’s cathedral, we show our unity with the Pope and our love and respect for him, as well as our obedience and faithfulness to the teachings of the Catholic Church.
It also shows that we are united with each other in the Universal Church. St. Paul described this unity in the Church in the 2nd reading as God's Temple with the Spirit of God living in us and uniting us.
Henceforth, it is our duty and mission to keep ourselves free of sin and defilement so as not to turn God's house into a market or, worst still, into a thieves' den.
More importantly, we must be united in heart and mind, and worship in Spirit and truth, so that the Church would be like what is described as the Temple in the 1st reading - with living waters flowing out to bring about healing and reconciliation, and bearing fruits of life and love.