The Church doesn't build itself, nor is the 'Church' the authority for believers: God's Word is

John 4:39 And many of the Samaritans of that city believed in Him because of the word of the woman who testified, “He told me all that I ever did.” 40 So when the Samaritans had come to Him, they urged Him to stay with them; and He stayed there two days. 41 And many more believed because of His own word.
42 Then they said to the woman, “Now we believe, not because of what you said, for we ourselves have heard Him and we know that this is indeed the Christ, the Savior of the world.”