Do not turn my God into a three-headed monster!

Today again, while searching for videos about the Trinity and leaving comments,
I came across a post like this.

Three persons are one God?
Please don’t turn my God into a three-headed monster!

Among those who came out in the Exodus,
the only ones who entered Canaan were Joshua and Caleb.
Likewise, among those who shout that they praise the Triune God,
there are occasionally people whose hearts are different, like Joshua and Caleb.

Even if an angel comes down from heaven,
if it is not the gospel that God has appointed, there is a curse upon it,
yet people seem to think like this:

“No, if that gospel were wrong, would there really be this many people?”
“No, could it really be wrong when they believe in Jesus so fervently?”
“No, how could someone who doesn’t believe in God read the Bible, pray, and be so devoted to church?”
“Someone like that probably already knows the gospel even if I don’t tell them…”
“Well, what if it’s a little different… they’re so devoted anyway…”
“That God is that God, what difference does it make…”
“I went to church my whole life too what’s the problem if my concept of God is a bit different…”

Jesus said, “For judgment I have come into this world,
so that the blind will see and those who see will become blind.”
Some of the Pharisees who were with Him heard this and asked,
“What? Are we blind too?” Jesus said to them, “If you were blind, you would have no sin;
but now that you say, ‘We see,’ your sin remains.”   (John 9:39–41)

“I told you that you would die in your sins; for unless you believe that I am He,
you will indeed die in your sins.”  (John 8:24)

But even if we or an angel from heaven should preach a gospel other than the one we preached to you,
let him be accursed!   (Galatians 1:8)