Psalm 103:19 The Lord has established his throne in heaven, and his kingdom rules over all.
When we see similar words at the beginning of the Lord's Prayer, we don't often go back to our Old Testament to see where they come from...
Jesus based all He taught on the words God had already given the Israelites through the prophets and kings...
We need to reconcile both 'halves' of our bibles to see the whole picture Jesus was trying to teach us. Don't ignore parts of the bible because you think they are too difficult to read!