So let’s imagine an alien has, in fact, come to earth. It does not understand how humans grow & change over time because the members of its species, and all life on its planet, reproduce asexually. They just split in two, so they are always “born” as mature adults. No distinctions are evident between the parental unit and the resulting offspring.
It’s the same with the Catholic Church if we don’t know the history; if we don’t see the Church as the mustard seed we read about in (Matt 13:31). Remember too what Jesus said to The Twelve in John 16:12-13, "I still have many things to tell you, but you can't bear them now. But when He, the Spirit of truth, comes, He will guide you into all the truth…” Why could they not bear them now? The Holy Spirit had not come yet AND because growth takes time. The developments in doctrine such as the Trinity, Hypostatic Union, Mary as Theotokos and the Canon of Scripture ALL took centuries.Transport an original Apostle, or any first century Christian, to the Vatican, or to visit other Catholic churches and institutions and they would be stunned at the size and look of it. Show them a copy of the current Catechism of the Catholic Church and they would be stunned at the knowledge in it. In fact, some early Christians might even conclude that this modern church is an imposter.
Christians today may reason that we need to get back to how early Christians did things 20 centuries ago, or at least, how they imagine they did things. The Church is too complex now, too many things “added-on” to what should be a simple faith. All you need is Love. Let’s remove the unnecessary doctrines, disciplines, liturgy, hierarchy, traditions and sacraments. Let’s just meet in our homes, sing some hymns, read some scripture, say some prayers, enjoy some fellowship, eat some bread and drink some wine.Not that the Church is necessarily “full grown” at this point in history, but all this reminds of an adult trying to become a baby again. Who needs complex balanced meals when we can just drink milk? Who needs intricate language to express ourselves when we can babble and scream? Who needs clothes when we can be naked? Who needs bathrooms with indoor plumbing when we can use diapers?
There is nothing wrong with being an infant when you are an infant, but there is something wrong (or undeveloped) about an adult trying to become an infant again. What comes after does not destroy what comes before. What comes after finds its reason for being in what comes before.