For the Messiah did not enter a sanctuary made with hands (only a model of the true one) but into heaven itself, that He might now appear in the presence of God for us.
References for Hebrews 9:24
He did not do this to offer Himself many times, as the high priest enters the sanctuary yearly with the blood of another.
Otherwise, He would have had to suffer many times since the foundation of the world. But now He has appeared one time, at the end of the ages, for the removal of sin by the sacrifice of Himself.
And just as it is appointed for people to die once-and after this, judgment-
so also the Messiah, having been offered once to bear the sins of many, will appear a second time, not to bear sin, but to bring salvation to those who are waiting for Him.
References for Hebrews 9:28