The land of Canaan had been the fulfillment of God's promises in the days of Joshua, and when God speaks of fulfilling kingdom promises, there is always land involved.
"In that day the Branch of the LORD shall be beautiful and glorious; and the fruit of the earth shall be excellent and appealing for those of Israel who have escaped." - Isaiah 4:2
When Israel departed from the Lord, she lost her land - but there were many promises of that land being restored. In the New Covenant, we are not to replace "land" with "heaven." We are supposed to replace "land," that is, the little peace of Palestine, with "the world."
God has given us a fruitful land. Jesus is Lord of heaven AND earth. One day, that will be completely manifest in a glorious resurrection of all things and the reuniting of heaven and earth. Until then, God's people, the New Israel, are to be stewards of this land, the world - making her more and more fruitful in every way a land can be (agriculturally, yes, but also as a means of providing life, cities, and relationships where Gospel hope flourishes).
We are to do so by means of the Word of God in the power of the Spirit of God - just like at creation.