Hebrews 9:23-28

Therefore it was necessary for the [earthly] copies of the heavenly things to be cleansed with these, but the heavenly things themselves required far better sacrifices than these. For Christ did not enter into a holy place made with hands, a mere copy of the true one, but [He entered] into heaven itself, now to appear in the very presence of God on our behalf; nor did He [enter into the heavenly sanctuary to] offer Himself again and again, as the high priest enters the Holy Place every year with blood that is not his own. Otherwise, He would have needed to suffer over and over since the foundation of the world; but now once for all at the consummation of the ages He has appeared and been publicly manifested to put away sin by the sacrifice of Himself. And just as it is appointed and destined for all men to die once and after this [comes certain] judgment, so Christ, having been offered once and once for all to bear [as a burden] the sins of many, will appear a second time [when he returns to earth], not to deal with sin, but to bring salvation to those who are eagerly and confidently waiting for Him.