The Incarnational Gift That Keeps on Giving, The Catholic Church
Christianity is incarnational. As John stated "the Word became flesh and dwelt among us." Paul further elaborates on this theme in his letter to the Phillipians.
"Who, being in the form of God, thought it not robbery to be equal with God:
But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross."
Through salvation history God has shown us that He is incarnational. Since we as humans are made of this "stuff" called flesh, God uses the flesh and things of the earth to communicate His grace to us.
In direct opposition to Gnostic philosophy, we believe God created us and the things of earth, therefore the flesh is not evil but is good!
God came to earth in the flesh of a crying, wet and smelly baby. (Luke 2:7)
He uses water to wash away our sins through baptism (John 3:3-5 1Peter 3:21)
He uses the ears of men to hear our confession and the lips of man to offer us His absolution of our sins (John 20:23). (Matt 18:18)
He uses the elements of bread and wine to be changed into His body and blood. (John 6:53-57)
He uses the one-flesh union of a man and woman to confer the sacrament of marriage. (Matt 19:5-6)
He uses the laying on of hands to pass on His authority to men which began with Peter and apostles. (Matt 16:18-19)
He used sinful men to start a visible Church that the gates of hell would not prevail against.
As a Catholic, the belief in a church that is one, holy, catholic and apostolic is deeply rooted in this incarnational nature and activity of God. Once I was able to understand that God pours out His grace through the "stuff of earth," it became easier for me to accept that He has founded His church on men and continues to infuse His grace through this visible structure, made of..... dare I say, flesh.
Perhaps the reason that some rail against the organization and very visible structure of the Catholic Church is their inability to appreciate this overarching incarnational aspect of Christianity.
As a non-Catholic for many years, I was probably more aligned with a gnostic versus incarnational view of Christianity. I had believed that Christ started a church but thought it was invisible. I thought of it more as a spiritual entity vs. a physical, living, breathing and durable structure of laity, priests, bishops lead by Christ's vicar, the pope. The Catholic belief that Jesus started His Church on Peter and continues it through apostolic succession is a direct extension of this incarnational view of how God delivers His grace to and through man.
"Where the bishop appears, there let the people be, just as where Jesus Christ is, there is the Catholic Church." Ignatius of Antioch (student of St. John the Apostle), 107 A.D., Letter to the Smyrnaeans.