First, I apologize for not getting back to you sooner. I'm still learning how to get around this site, and I just now saw your response.
I think it's possible to click on someone's name, and see their posts. I'm going to go through mine, and I think there will be some things that will be helpful. I'm not trying to put you off -- it's just kind of late here, and I want to put more thought in this, when I can write more, and I'm thinking more clearly, LOL!
One thing I can say, is that it literally took a revelation from God to believe in the Trinity. I know there were people praying for me. I also believe that many, if not most, of people that join churches like JW, 7th day Church of God, and others that don't believe in the Trinity, are people that truly do want the Truth, but they get side-tracked. These churches often come up with their own "translations" of the Bible, which then supposedly confirms their beliefs. I was one of those people that had a problem with the Bible being the only source of Truth. Using the Bible as a weapon to "prove" doctrine, to the exclusion of 2,000 years of Tradition, teaching of the Fathers, and history, is a real problem. But especially in the U.S.A., "sola scriptura" has produced tens of thousands of groups that think they have the "correct interpretation" of the scripture.
JW's are one of those many groups that had someone decide that they had a special gift of that "correct interpretation" of the Bible. Somehow, they are able to buy into the idea that God was not able to keep His Church intact for 2,000 years. Yet, Jesus Christ said, speaking of the Truth of His Teachings and His Life, "Upon this Rock I establish my Church, and the gates of hell will not prevail against it." That doesn't indicate 1800 years of apostacy, until God revealed it to someone in the 1800's. There were so many "visions" and "revelations" during that time, and they all popped up outside of any kind of Authority of the Church.
I'm sure you know all these things -- they are just things that mean a lot to me, since because of them I was led into heresies, the worst of them being Aryanism, that Jesus was not God.
I believe it is Schmemman (I'll look it up) that says if someone is truly, in his heart, seeking Truth, that no matter what they go through, no matter what religion, that they will eventually run right into the arms of Jesus Christ. That is what happened to me, and when He took me in His Arms, I KNEW I was in the Arms of GOD, that GOD had walked the earth. That began my five years search for the Truth Body of Christ, and for the Holy Mysteries.
I came from religions that were as heretical and in error as JW's -- and I am Home. I am being baptised in the TRINITY, Crismated, and will receive the Precious Blood and Body of Christ in the Eucharist. I KNOW that the gates of hell did not prevail against His Church. Glory be to GOD!!
I will pray for your friend.