You confuse the "how" with the "what." Sacraments are how we are saved by Jesus. They would not exist and would have no salvific power were it not for Jesus' Sacifice.
Can you understand that?
With all due respect: BUNK. That is competely unbiblical. If sacraments are the 'how' we didn't need the cross! All God needed to do was institute the sacraments and spared His son a grueling death. Can't you see that???