Going from the twenty-third Psalm to the twenty-fourth Psalm is like moving from Jesus to Joshua. In the twenty-third Psalm, Christ is wearing His shepherd's hat. In the twenty-fourth Psalm, Christ is wearing His warrior's helmet.
My opinion is that the "ancient doors" are the hearts of human beings. Why are they ancient? Because they have not changed from the beginning of man on the earth. An additional thought is this: It is in the present hour that God is revealing His plan to live in us, to place His Throne in us. Since this opportunity is available to every one of God's elect both on earth and in the spirit world, some of the recipients have lived for thousands of years.
From the beginning of the creation, people have attempted to conduct their own lives, using their own wisdom, experience and strength. It is only now, it seems, that we are understanding that man is not to live by bread alone but by every Word of God directed to him or her.
We all have a "throne room" in our personality. It was not built for us. When we sit on that throne without the Lord, our life cannot attain to the fullness of righteousness, love, joy, and peace no matter what we accomplish during our time on the earth.