Because He told us to. We Catholics do not scrub all of scripture through our finite and fallible minds and reject or modify what we find difficult. We have faith in Him and believe.
See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is [administered] either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude also be; even as, wherever Jesus Christ is, there is the Catholic Church." - St. Ignatius of Antioch, Letter to the Smyrnaeans, 8.
Peace be with you.
But which Ignatius wrote that??? The original one or the forger who added all the Catholic references 250 years after the real Ignatius died???