We already saw a conversation where God tells Abraham that the world exists in the merit of the sacrifices in the Temple. Here we have the continuation of this conversation. Abraham asked, "That answer is good when the Temple is standing. But without the Temple, if the Jews sin - you will destroy them!" God replied that while the Jews are reading the Torah portions, which contain sections about offering, it is as if they were bringing the offerings. That is why they will be forgiven.
Art: Jews Mourning in a Synagogue by Sir William Rothenstein