You have asked about this sentence (9:24) from the Letter to the Hebrews: "For Christ has entered, not into a sanctuary made with hands, a copy of the true one, but into heaven itself, now to appear in the presence of God on our behalf."
The Letter to the Hebrews is a discourse (author unknown) defending the spiritual superiority of the message of Jesus Christ over the existing Jewish faith out of which it grew. It's long and complex, with a vision that sees Jesus Christ—in terms of the Jewish faith—as both high priest and sacrifice, heir to a spiritual tradition even more ancient that Judaism and superior to the older religion because it is more directly linked to the Power of God.
Metaphysically, this part of the Letter to the Hebrews is emphasizing the superiority of the direct connection with God represented by the Christ over the physical structures and religious dogmas that were necessary to guide us up to the point at which we were ready and able to fully grasp our innate Oneness with God through the indwelling Christ that is our true identity.
In 9:11 we read "But when Christ appeared as a high priest of the good things that have come, then through the greater and more perfect 'tent' (not made with hands, that is, not of this creation) he entered once for all into the Holy Place, taking not the blood of goats and calves but his own blood, thus securing an eternal redemption." In short, when we fully embrace the Christ Presence within as our true identity, then -- as Jesus promises the Samaritan women at John 4:24—we will worship God "in spirit and truth." We will know our innate Oneness with God, and won't need "a sanctuary made of hands." We will be offering up our own blood—committing our full life force to the expression of Christ that we truly are. When we are fully the Christ in expression we are, indeed, in the kingdom of heaven. The intermediaries that are helpful and important at earlier stages of our spiritual awareness dissolve away, and we are left experiencing and expressing the creative Light and Love of God that are our only true reality.