Hebrews 10:16 This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them; 17 And their sins and iniquities will I remember no more. 18 Now where remission of these is, there is no more offering for sin. 19 Having therefore, brethren, boldness to enter into the holiest by the blood of Jesus, 20 By a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh; 21 And having an high priest over the house of God; 22 Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
Very good. And we have Revelation 21: 22* n I saw no temple in the city, for its temple is the Lord God almighty and the Lamb. 23* The city had no need of sun or moon to shine on it,o for the glory of God gave it light, and its lamp was the Lamb. 24The nations will walk by its light,* and to it the kings of the earth will bring their treasure.p 25During the day its gates will never be shut, and there will be no night there. 26The treasure and wealth of the nations will be brought there, 27but nothing unclean will enter it, nor any[one] who does abominable things or tells lies. Only those will enter whose names are written in the Lamb’s book of life.q
We have assurance of faith, not salvation. We have the hope of salvation of St. Paul, not the assurance of salvation of Calvin. But there is a process of being made perfect; that process is begun with the acceptance of Christ. But it is a journey and not finished unless and until the Judge of All bestows His mercy upon us at our Judgement.
You actually didn’t understand the term “entering the holiest”? That is not a literal building here on earth. It’s the right to come before the throne of God through the blood of Christ. All who rely solely on the blood of Christ for salvation can go before the throne of God whereas prior to Christ’s death only the High Priest could and then only once a year and after ceremonial cleansing.