Most Christians at one time or another imagine that there is a perfect church somewhere.
There is not. Not here on earth, anyway.
And I'm not contrasting a "visible" and an "invisible" church: that's a human invention. No, the true church, God's people, the "pillar and ground of the truth" (cf. I Timothy 3.15) strains for holiness while at the same time praying for forgiveness and being encumbered by sins.
Those who wish to restore an imagined first century Christianity should read and re-read I and II Corinthians.
And with the imperfections of the church, we'll also have to deal with false prophets. For reasons known to themselves, false prophets always seek to put themselves in the midst of God's people.
And so God's people must discern: true from false.
I'm currently reading through 2 Kings, and was struck by this in the account of the dealings St. Elisha had with the Shunamite woman. The woman is not identified, but she is called "great." (2 Kings 4.8)
The time of the kings was no different from ours: there were plenty of false prophets out to fleece God's people. And one of the tasks of God's people is to discern the true from the false, and to avoid false prophets.
One of the blessings of the creeds is that they give us a guideline, a measure, a rule by which we can know true and false teachers. We are also given the example of the Bereans (in Acts 17.11) who searched the scriptures to determine if Paul and Silas were true teachers of the church.
And the Shunamite woman makes a determination: "this is an holy man of God, which passeth by us continually." (2 Kings 4.9) Her response is to offer hospitality and kindness to this true teacher of the church, and St. Elisha blesses her to have a son in her old age.