Christ “entered once for all” on the cross, in Jerusalem.
Now that he is risen, in heaven, Christ “enters” CONSTANTLY and presents himself and his death to the Father.
The Mass is a participation in what Jesus is doing NOW in heaven. It is not an attempt to repeat what Jesus did once for all, in Jerusalem.
The Mass is offered again and again, all over the world, in obedience to Christ’s words: “Do this in memory of me.”
Those who refuse to obey Jesus in this evidently do not believe the words of Scripture.
scripture please