We are members of the Church. As such, through the Eucharist, our lives are united to Christ and his offering. The sacrifice of Christ made present on the altar enables all Christians to join themselves to his offering.
So, each one of us helps Mother Church to make her sacrifice. We jointly offer our praise, our sufferings, our prayers, and our work together as a community of faith. And through the sacramental mystery, these little offerings of ours are joined to the one supreme offering of Jesus: his death on the cross.