Many arguments have been presented stating that because something—in this case the acceptance of the perpetual virginity of Mary—has been promoted or accepted, “from the beginning,” that it is therefore true or right. But even Peter, the foundation of the Church, told lies, "from the beginning."
Matthew 26:33-35,
“Peter answered and said unto him, Though all men shall be offended because of thee, yet will I never be offended. Jesus said unto him, Verily I say unto thee, That this night, before the cock crow, thou shalt deny me thrice. Peter said unto him, Though I should die with thee, yet will I not deny thee. Likewise also said all the disciples.”
Matthew 26:69-75,
"Now Peter sat without in the palace: and a damsel came unto him, saying, Thou also wast with Jesus of Galilee. But he denied before them all, saying, I know not what thou sayest. And when he was gone out into the porch, another maid saw him, and said unto them that were there, This fellow was also with Jesus of Nazareth. And again he denied with an oath, I do not know the man. And after a while came unto him they that stood by, and said to Peter, Surely thou also art one of them; for thy speech bewrayeth thee. Then began he to curse and to swear, saying, I know not the man. And immediately the cock crew. And Peter remembered the word of Jesus, which said unto him, Before the cock crow, thou shalt deny me thrice. And he went out, and wept bitterly.
And Peter, even though cautioned not to, “live by the sword,” and having been taught the importance of forgiveness, nevertheless condemns a widow for lying.
Matthew 26:51-53,
“And, behold, one of them which were with Jesus stretched out his hand, and drew his sword, and struck a servant of the high priest’s, and smote off his ear. Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword. Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?”
Matthew 18:21-35,
“Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times? Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven. Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants. And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents. But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made. The servant therefore fell down, and worshipped him, saying, Lord, have patience with me, and I will pay thee all. Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt. But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.
And his fellowservant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all. And he would not: but went and cast him into prison, till he should pay the debt. So when his fellowservants saw what was done, they were very sorry, and came and told unto their lord all that was done. Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou desiredst me: Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee? And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him. So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses.”
Acts 5:1-11,
“But a certain man named Ananias, with Sapphira his wife, sold a possession, And kept back part of the price, his wife also being privy to it, and brought a certain part, and laid it at the apostles’ feet. But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God. And Ananias hearing these words fell down, and gave up the ghost: and great fear came on all them that heard these things. And the young men arose, wound him up, and carried him out, and buried him. And it was about the space of three hours after, when his wife, not knowing what was done, came in. And Peter answered unto her, Tell me whether ye sold the land for so much? And she said, Yea, for so much. Then Peter said unto her, How is it that ye have agreed together to tempt the Spirit of the Lord? behold, the feet of them which have buried thy husband are at the door, and shall carry thee out. Then fell she down straightway at his feet, and yielded up the ghost: and the young men came in, and found her dead, and, carrying her forth, buried her by her husband. And great fear came upon all the church, and upon as many as heard these things.”
Just because something has been done, “from the beginning,” doesn’t necessarily make it right.