The Holy Eucharist acts in the soul in the same way that ordinary food nourishes the body. Life in the body begins with generation, and then our body grows to full maturity while we keep receiving food for our sustenance. Similarly, there is a spiritual generation into the life of grace…We need spiritual food…our food is the Eucharist. The external form of food is most appropriate to signify the union with Christ which is effected in this sacrament. However, there is a discrepancy in the comparison of the Eucharist with food. Whereas food is assimilated by the person fed, in the case of the Eucharist the person receiving it becomes assimilated into Christ. The Eucharist also directs our eyes toward our last destination. The fullness of the New Covenant will reach its culmination in the new and everlasting Jerusalem, in heaven, where all the chosen ones shall be gathered in the eternal banquet.
Charles Belmonte: Understanding the Mass, pp. 16-17