Today, what does the "Lamb of God" mean? Why Jesus is called "the Lamb" and how could this "Lamb" take away the sins of the world?

In Isaiah 53,7, God’s servant song compares the servant who suffers with a lamb led to the slaughter: "and as sheep before its shearer is silent, so he did not open his mouth". Yet, even more important is that Jesus was crucified during the Passover and He should therefore appear as the true Paschal Lamb, in which, what the Paschal lamb meant in the exit from Egypt, was fulfilled. Ever since Easter, the symbolism of the lamb has been fundamental to understand Jesus Christ.

—If in the destitutions of the Egyptian oppression the blood of the Paschal lamb had been conclusive for the liberation of Israel, He, the Son, who has become servant – the shepherd who has turned out to be a lamb – has also become a pledge not only for Israel, but for the rescue of the world, of all mankind.