Pope Francis said Wednesday that the Kingdom of God is the greatest force in the world, but it is humble, almost invisible, and slow-growing.

"'Thy Kingdom come!' repeats the Christian insistently … sometimes we ask ourselves: why is this Kingdom being realized so slowly?" Pope Francis said March 6.

"God is not like us, God has patience," he explained to the pilgrims in St. Peter's Square. During his general audience on Ash Wednesday, the pope reflected on the line, "Thy Kingdom come," in a continuation of his weekly catechesis on the "Our Father."

To say, "Thy Kingdom come," is like saying "We need you, Jesus," the pope said. "We need you, Jesus … that everywhere and forever you may be Lord among us!"

"Signs of the coming of this Kingdom are many, and all positive," Francis said. "Jesus himself indicates these signs: 'The blind regain sight, the lame walk, the lepers are cleansed, the deaf hear, the dead rise again, the Gospel is proclaimed to the poor.'"

He called on Catholics to sow the seed of God's word in the midst of their sins and failures. "Give it to people who are defeated and bent by life, to those who have savored more hate than love, to those who have lived useless days without ever understanding why," he said.

"Let us give it to those who have fought for justice … to those who have concluded that they have fought for nothing and that evil always dominates in this world," he continued.

Pope Francis noted that though "the Kingdom of God is certainly a great force, the greatest that there is," it does not fit with the criteria of the world.

The Kingdom of God "is like a grain of mustard, so small, almost invisible, but it carries within it the explosive force of nature, and once grown it becomes the greatest of all the trees of the garden," he said, quoting the Gospel of Matthew.

Pope Francis described the symbolism of the Kingdom of God as a seed as "eloquent."

"One day the peasant sinks it into the earth (a gesture that looks like a burial), and then, asleep or awake, by night or by day, the seed sprouts and grows," he said. "A seed that sprouts is more the work of God than that of the man who sowed it."

He continued: "God always precedes us, God always surprises us. Thanks to him after the night of Good Friday there is a dawn of Resurrection capable of illuminating the whole world with hope."

The desire for the coming of God's Kingdom, Francis explained, flows "from the very heart of Christ, who began his preaching in Galilee proclaiming, 'This is the time of fulfillment. The kingdom of God is at hand. Repent, and believe in the gospel.'"

"May the Lenten journey we begin today bring us to Easter with hearts purified and renewed by the grace of the Holy Spirit," Pope Francis said.