The way the term trinity was used was in a mocking manner of derision with relation of three Christian members. It doesn't matter to them. What matters is that God might just reject the rejects that speak of Him that way.
I know that God can forgive all sins. Jesus paid for them all, including using His name in vain and sins of those who rejected Him. When someone goes so far as to attribute to men the term we use to describe the Father, Son and Holy Spirit, John 5:7, IMHO they are pushing the envelope and should be corrected that others may fear. There's absolutely no fear of God's judgement on this forum with some. Therefore the blasphemies have become more common even the short time I've been a member. I doubt if the socialist forums are this bad. People don't need to see that garbage. Adults should use at least a small amount of self control. When they don't, it shows hard their heart has gotten.
I grew up with no teaching on this topic that I recall. Here's one sermon that covers the topic pretty well.
