The Kingdom of Yahweh was the central image in Yahshua's teaching, as clearly seen in Mark 1:14-15, which is a summary of all of Yahshua's preaching. The Kingdom of Yahweh is the heart of the summary.
And after John was delivered up, Yahshua came into Galilee proclaiming the good news of the kingdom of YAHWEH, and he said, The time is complete and the Kingdom of YAHWEH has arrived. Repent and believe in the good news Mark 1:14-15.
Here are literature pieces revolving around the Kingdom.