Isn't that basically what the Mormons and JWs and what have you say to validate their various beliefs? You (and I) don't have the gift of knowing the BoM is Scripture for instance.
I'll be painfully blunt: I earnestly believe that Jesus Christ is God come in the flesh and that no one comes to the Father except through Him but I when confronted with the Shepherd of Hermes and 2 Peter (for example) couldn't tell which is inspired and which isn't. Does this mean I'm damned because I accept the authority of the Roman Church to tell me what is and isn't canonical?
And yet there's nothing more I hope for than to see God face to face. Just let me see Jesus and throw my unworthy self at His feet and I will be happy for all eternity.
Your first hearing of the words of God may very well come with the testimony of other believers - e.g. Catholic Church, evangelist, minister, family member, friend.
Praise God!!!
But it is not their testimony which enlivens you "in" Him - it is His own words that do that:
Give us this day our daily bread. Matt 6:11
I am that bread of life. John 6:48
It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, [they] are spirit, and [they] are life. John 6:63
Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life. John 5:24
I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me. - Galatians 2:20
This is the first and great commandment.
And the second [is] like unto it, Thou shalt love thy neighbour as thyself.
On these two commandments hang all the law and the prophets. Matthew 22:35-40
Ye shall not add unto the word which I command you, neither shall ye diminish [ought] from it, that ye may keep the commandments of the LORD your God which I command you. Deuteronomy 4:2
For ye are yet carnal: for whereas [there is] among you envying, and strife, and divisions, are ye not carnal, and walk as men? For while one saith, I am of Paul; and another, I [am] of Apollos; are ye not carnal?
Who then is Paul, and who [is] Apollos, but ministers by whom ye believed, even as the Lord gave to every man?
I have planted, Apollos watered; but God gave the increase. So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase. I Corinthians 3:1-7
I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty. - Revelation 1:7-8
And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you. Exodus 3:14
Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. - John 8:58
As soon then as he had said unto them, I am [he], they went backward, and fell to the ground. John 18:6
Remember the former things of old: for I [am] God, and [there is] none else; [I am] God, and [there is] none like me, Declaring the end from the beginning, and from ancient times [the things] that are not [yet] done, saying, My counsel shall stand, and I will do all my pleasure: - Isaiah 46:9-10