Of course there is that concern.
The other day a member of a self-proclaimed Christian group approached me after Mass and tried to convince me that Our Lord Jesus was not God, dutifully quoting passages of Scripture by heart as he opened the Bible in front of me to allow me to read them.
I told him that I did not remember Scripture so thoroughly, but I did recall that the Lord said: “I and the Father are one”, and that Thomas did say to Him: “my Lord and my God”, without being rebuked, but rather, meriting a compliment and a blessing for all believers that would follow.
After some further discussion, I tried to explain to him that this doctrine he had learned was a modern doctrine brought forth by men, which terribly contradicted the apostolic tradition and the writings of the Church Fathers, to which he laughed at me saying that the Church Fathers were just men, and raising up his Bible, saying: this is what saves us, this is where the truth is!
And I told him, patiently: who wrote that?
He stopped and said: huh?
I said: who wrote that? Who put it together? When was the first Bible put together?
He realized he was on slippery ground and said: “oh, that doesn’t matter…” but I didn’t let him run away and I insisted: "it does matter! The Church put the Bible together. It took centuries. When you quote, say, the letter of Paul to the Thessalonians, do you think the Romans or the Colossians had any knowledge of its contents? And when there was a dispute amidst the faithful, do you think they went and read the Hebrew scrolls of the Scripture and tried to find the doctrine in there? Even after the Canon of the Bible was agreed upon, do you not know that the book had to be handwritten and that there were only few copies kept as true treasure? Did not the people rather pay close attention to the apostolic teaching of the twelve and of those elders whom they have appointed (ex Paul, Barnabas) and the other elders whom in turn they had appointed?
Not knowing what to reply (and kind of embarassed before his young apprentice, given that he must have been some twenty years older than me) he said: but the truth can be found here, in the Bible! And I replied: according to the Bible you claim Jesus Christ is not God. Others claim he is. Others claim there is no Holy Spirit. Others claim God is One in Three Persons. The truth is definitely there, but which interpretation is truthful? Who has the authority to say which is the biblical truth and which is an error?
But that didn’t help at all. He was too focused on the deification of those writings he was holding in his hands, forgetting that they were the mere word of God, not the Word of God who in the beginning was with God and was God, and who took flesh, and who did many more things than could ever be written down in books, and who said to his apostles that those who rejected them rejected Him, for to them was given to know the secrets of the Kingdom, to them the Holy Spirit of Truth was given to reveal many more things to them. It was very sad in the end for me, but such are the mysterious ways of the human heart.