Why do we need the sacraments? Didn't Jesus die for us already?

Jesus died on the cross to save mankind, but he also instituted the sacraments to save mankind. Why did he do both?? Well, when Jesus died on the cross he opened to mankind the opportunity to save ourselves. His one death is worth infinitely; this means that every time we sin, Jesus's one death still keeps that door open to redemption whereas whenever Adam and Eve sinned, they were completely shut out until Jesus died for our sins. Now because his death does not completely redeem us, we need the sacraments. The sacraments rebuild our bond with God through the reception of graces: actual and sanctifying grace. Jesus's death allows us to be redeemed while the sacraments actually rebuild our relationship with God.