“The early christians left behind evidence of their beliefs, the trinity being among them....
http://www.carm.org/doctrine/trinityquotes.htm";
Also, many of the quotes there, especially the earlier ones, do not claim three persons in one being or of one substance. If you examine a broader range of what they said, you will find many of them teaching things that are contrary to the creeds that came later on, for example Justin Martyr taught that Christ was second in rank to the Father, and the Holy Ghost was third in rank, contrary to the co-equal claims of the creeds.
“ranking” does not claim being separate in the godhead.
Our creed does make distinctions...
“We believe in One God, the Father Almighty, Maker of Heaven and Earth, of all things seen and unseen....”
...”We believe in Jesus Christ, the only begotten Son of the Father. God from God, Light from Light, true God from true God. Begotten, not made, one in being with the Father.”....
“We believe in the Holy Spirit, the Lord, the Giver of Life, Who proceeds from the Father and the Son...”
Even in scripture, Jesus referred to a sort of “rank” by claiming to be one with the Father, but also claiming He could only do the will of the father.
So pointing out differences in the 3 persons is not a denial of the trinity.
You certainly won’t come across early writings claiming God the Father was a human being who conceived Jesus through intercourse with Mary.