Ps 85 10 Love and faithfulness meet together;
righteousness and peace kiss each other.
11 Faithfulness springs forth from the earth,
and righteousness looks down from heaven.
12 The LORD will indeed give what is good,
and our land will yield its harvest.
13 Righteousness goes before him
and prepares the way for his steps."

This is the ultimate unity of heaven and earth. This is describing what happened in Christ death and resurrection. We must understand that the events of this earth are never limited by the perfect experience of the unity of God. The Psalms are laws, covenants , curses, promises and statutes that control the kingdom that dwells in our hearts. Our problem is that we limit God by our view very small view in our time sequence.. We actually think that the world is like God. You see God is eternal. He existed in eternity before the world was formed. God describes everything in one view. He is not limited by the progress of time. He sees the beginning from the end. Now listen , in Gods view all things are justified by His cursing and blessing. This is what brings all things to unity.
You see here that love is in the heavens and faithfulness is on the earth. Now listen God made the earth for mankind. He gave the earth and its valuables for us to use and rule over. But the problem is that we are subject to the opposition of sin and corruption. The truth is that we can do nothing without God. We are absolutely dependent upon God. We cannot survive without love from heaven united with faithfulness of His creation. His gifts to us are dependent upon His sustaining and ordering all things. Our problem is that we really do not believe there is a legal pronouncement from heaven on the laws that sustain all things. We are looking to mankind to create the health and the moral structure that gives us peace. But the truth is that God orders all things because He must justify Himself as the perfect Governor.
The Psalmist is declaring the basis of his confidence is in the legal justification of God that prevents the universe from destroying all mankind. The bases of God unifying His work of sustaining all things and providing all things is that God covenanted with His elect to provide for His people with the promise that He would be subject to the harm of man if He were not faithful!!!!!Here the Psalmist is declaring that when he pronounces the laws, covenants ..etc that He experiences the total unity of God legally perfect kingdom that reorders all things in this sin and corrupted world. So he can pronounce the perfect kingdom that is the only hope of finding unity in this world and perhaps experience it in actually in the future as we live under the governments of this world. When the works of God are united with our present experience then we experience the ultimate unity and pleasure of this world.