“Now after John was arrested, Jesus came into Galilee, preaching the gospel of God, and saying: ‘The time is fulfilled, and the kingdom of God is at hand: repent, and believe in the gospel.”’ “To carry out the will of the Father Christ inaugurated the kingdom of heaven on earth.” Now the Father’s will is “to raise up men to share in his own divine life”. He does this by gathering men around his Son Jesus Christ. This gathering is the Church, “on earth the seed and beginning of that kingdoms”.
Christ stands at the heart of this gathering of men into the “family of God”. By his word, through signs that manifest the reign of God, and by sending out his disciples, Jesus calls all people to come together around him. But above all in the great Paschal mystery – his death on the cross and his Resurrection – he would accomplish the coming of his kingdom. “and I, when I am lifted up from the earth, will draw all men to myself.” Into this union with Christ all men are called.
From the Catechism of the Catholic Church 541-542