the laws of sacrifices required two important things -- 1, that we perform the sacrifice in a state of ritual purity, a state that we are not in now, and 2, that we perform it in a place that God commands us to, and not anywhere else. That place shifted over time, from the tabernacle in the desert to the temporary one in Shiloh and eventually to the temple in Jerusalem. As the temple has been destroyed, we don't have access to the only place where we are allowed to sacrifice.
Just a side note, the lamb sacrifice of Passover had nothing to do with sin.