The Heavenly Jerusalem is the City of the Living God

"You have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, to an innumerable company of angels, to the general assembly and church of the firstborn who are registered in heaven, to God the Judge of all, to the spirits of just men made perfect, to Jesus the Mediator of the new covenant, and to the blood of sprinkling that speaks better things ... " Hebrews 12:22-24 NKJV "This heavenly Jerusalem is the Church, that is to say the number of all believers throughout the world, having one and the same Gospel, one and the same faith in Christ, one and the same Holy Ghost, and the same sacraments." ~ Martin Luther, Commentary on the Epistle to the Galatians (verse 4:26)