Abraham was saved by grace through faith, thus his salvation was eternally secure. He was also told that he would be a stranger and a pilgrim on earth, and would dwell in Canaan (the Land of Promise). He was also given a vision of the New Jerusalem, so that he would know where his eternal home was. See Hebrews 11. So he allowed Lot to choose where Lot would settle, and as we know, Lot made a very poor choice.
As to "the Kingdom" that is yet future (after the second coming of Christ). We are in the Church Age right now, and the Great Commission is the top priority of every Christian.
The Kingdom of God starts right here.
Do you believe Jesus came to die on the cross to forgive our sins...
And did He not also want to set up the Kingdom of God here in THIS LIFE?
Didn't He want to let God's light shine and attempt to make this earth a better place? Did He not teach us how?
Start with the beatitudes.
Mathew 5:3-10
Why did Jesus preach more about the Kingdom than anything else, including salvation?
Because He wanted us to have a better life right here,,,and if we would all adhere to Jesus' teachings, we would have a better life right here.