Mustard seeds are 1-2mm in diameter
and the plant grows to about 12 feet.
Photos courtesy of Gernot Katzer
Jesus compared the growth of his kingdom to the mustard seed planted in the ground which is the smallest of all seeds but grows into a large bush where the birds of the sky come to dwell in its branches.
Indeed Christ's kingdom began with a group of 12 men in Palestine but soon spread throughout the Roman Empire. Today 33% other people on the planet are Christians or about 2 billions. Only 17% or 1,050,000,000 are Catholics. As we can see 2/3 of the world does not believe in Christ. How are to understand Christ's teaching:
"No one can see the Kingdom of God without being born from above." (Jn 3:3)
"No one can enter the kingdom of God without being born of water and the Spirit." (Jn 3:5)
and the Church Dogmatic Statement:
"There is no salvation outside the Church."
The Church statement is not aimed at those who through no fault of their own do not know Christ and his Church but to those who knowingly refuse to enter the Church or who leave it.
At this time we must stop and reflect on the Jews and Christ's Kingdom. They were the first people called by God and are still God's people because God does not break his promises. They still look forward in hope to the coming of the Messiah. They are not now part of Christ's Kingdom on earth, but those who live in faith, hope and love will be brought to the full realization that Christ as their Messiah in glory.
And what about the Muslims? They believe in the God of Abraham whom they call "Allah, the Beneficent and Merciful". (The Koran ) They consider Mohammed as their prophet but also Christ as a prophet. They are also called into Christ's kingdom and if they live lives of faith with a good conscience they will arrive at eternal life.
In the Catechism of the Catholic Church we read:
through no fault of their own,
do not know the Gospel of Christ or his Church,
but who nevertheless seek God with a sincere heart,
and moved by grace,
try by their actions to do his will as they
know it through the dictates of their conscience
--those may achieve eternal salvation." (No. 847)
Christ King of the Universe