That there is a Temple in Heaven, we are told in Revelation 11:19, 15:5-8 and 16:1.

The New Jerusalem and Heaven are not the same.

       The New Jerusalem is the place that Jesus went to prepare for His Bride, the Church, and John declares that he saw it coming down out of Heaven.

The blood washed multitude is another class of the saved of the End-time.

        They do not represent the Church, for the Church has already been taken out in the rapture.

             They are a multitude save by the preaching of the Gospel of the Kingdom during the tribulation period. 

The Blood Washed Multitude
Revelation 7:9-17

"After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the Throne, and before the Lamb, clothed in white robes, and palms in their hands; and cried with a loud voice, 'Salvation to our God which sitteth upon the throne, and unto the Lamb.
And all the angels stood round about the Throne, and about the Elders and the Four Beasts, and fell before the Throne on their faces, and worshipped God, saying, Amen: Blessing and glory, and wisdom, and thanksgiving, and honor, and power, and might, be unto our God for ever and ever. Amen.
And one of the Elders answered, saying unto me, What are these which are arrayed in white robes? and when came they?
And I said unto him, Sir, thou knowest.
And he said to me, These are they which came out of the great tribulation, and have washed their robes, and made them white in the blood of the Lamb. Therefore are they before the Throne of God and serve Him day and night in His Temple: and He sitteth on the Throne shall dwell among them.
They shall hunger no more, neither thirst any more: neither shall the light on them, nor any heat.
For the Lamb which is in the midst of the Throne shall feed them, and shall lead them unto living fountains of water: and God shall wipe away all tears from their eyes."

The 'Elect' of Israel will be those who fear Christ's name, and who like Simon and Anna watched for His first coming, will be looking for the coming of their Messiah.

The Angel who is in charge of sealing the 144,000 comes from the east.

        This shows that the Sealed Ones are looking toward the sun-rising, as if looking for the fulfillment  of the promise in Malachi 4:2 ,
"Unto you that fear My name shall the sun of righteousness arise with healing in His wings."

Even though the 12 tribes of Israel were scattered and lost in and among all the nations, God knows where they are.

            And even though they may have lost the genealogy books and records, not being able to trace their tribal descendants, God
knows where they are and who is who, and in that day the angels will seal them according to their Tribes.

The 144,000, 12,000 from each Tribe, will be of the earthly Israel.

       It's the seed of Abraham, living at that time and not of a spiritual Israel.

Theirs isn't a secret discipleship.

In the same public manner, the followers of the Antichrist will be Sealed in their foreheads or on their right hands with the mark of the Beast which is the number of his name, or 666.

The Father's name is written, as the seal on the 144,000's, foreheads where others could see it.

The sealing of the 144,000 is not the Sealing of the Holy Spirit, that believers are sealed, but it is the Sealing at the hand of Angels.

        Jesus referred to it in Matthew 24:31.

We have an intermission in the breaking of the Seals that God's elect of Israel may be Sealed.

         There will be a 'remnant according to the election of grace' and God will reserve 144,000 of Israel who during the Tribulation Period will not bow their knee to the Antichrist.

The Interval Between the Sixth and Seventh Seals
The sealing of the 144,000.
Revelation 7:1-8

"And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
And I saw another angel ascending from the East, having the Seal of the Living God: and he cried with a loud voice to the four angels, to who it was given to hurt the earth and the sea, Saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads.
And I heard the number of them which were sealed: and there were sealed a hundred and forty and four thousand of all the tribes of Israel.

It is interesting to compare Jesus' "Olivet Discourse" of  Matthew 24:1-30 with the "Six Seals" of Revelation 6:1-17.

        The similarities are striking and proves the author of the discourse knew of the things that were to come to pass in the "Day of the Lord."

                 This is evidence of Jesus' deity.

Instead of repenting and crying for Salvation, the people will call on the mountains and rocks to bury them from the sight of the Almighty.

All the physical changes will cause a fear to fall on all men who will no long attribute the changes to natural law, but will see the 'hand of the Almighty' in it.

         To them the "Day of Judgment" will become a reality and in fear and terror they will hide themselves in the dens and rocks  of the mountains saying, "Fall on us and hide us from the face of Him that sits on the throne, and from the wrath of the Lamb, for the Great Day of His wrath is come, and who shall be able to stand?"

These physical convulsions will be the earth's 'travail pains' as she labors to bring forth the New Creation of the Millennial Age.

          Jesus said in Matthew, "In those days shall the sun be darkened (that is, its light obscured) and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens (the principalities and powers of the heavenly places, not the Powers and Kingdoms of the Earth), shall be shaken."

Also in Isaiah it says, "All the host of heaven (the stars) shall be dissolved and the heavens shall be rolled together as a scroll; and all their host shall fall down, as the leaf falleth from the vine, and as falling fig from the fig tree."

         These corresponds to the stars of heaven of this seal and probably refers to our atmosphere and to meteors and shooting stars similar to those we have seen periodically.