Why would the Mosaic system of law and temple worship come to an end when the King came?
When the King came, the Mosaic system of law and temple worship would fall by the wayside because the King would come in, the New Covenant would become a reality, and people would no longer have to study and witness, since everybody would be in right relationship with God.
Les explains that Stephen was proclaiming the coming of the King and the Kingdom. When that King would come, the whole format of the Mosaic system of law and temple worship would fall by the wayside. The New Covenant would become a reality, and there would be no further need to study and witness because everybody would be in right relationship with God. The religious section of Judaism rejected this, saying they would not let anything change the way they had always done things.