Negative. They are as lost as most everybody else.
Let me preface this with the fact I am not a Catholic, but a Bible believing Christian.
He is probably a Oneness Pentecostal or Apostolic. Either way his heresy is modalism and was condemned at Nicaea in 325 and outright rejected at Constantinople in 381. There are several wrong things have been said so here we go:
First, you are appealing to the fallacy of specificity. Yes the word Trinity does not appear in the Bible, but you know what other word doesn’t? Monotheism. Does that mean that the Christian faith isn’t monotheistic? Absolutely not. What it means is we sometimes give categorical names to theological truths we see in scripture.
Next Nicaea was not called to establish the doctrine of the Trinity, as it has its roots in ancient Judaism and the New Testament. Even the patristic fathers spoke of the Trinity. The counsel was called to address heresies that had popped up, mainly Arianism but also this heresy of modalism. The Nicene Creed was produced to officially codify into writing the long held belief of the Trinity. Ask yourself why would non-trinitarian heresies exist prior to Nicaea if the Trinity was invented at Nicaea? The fact is it goes all the way back to Jesus and had its roots in the Jewish understanding of the “Two powers in heaven” doctrine (go read up on that). Example Gen 19:24 “YHWH God rains down fire from YHWH out of heaven”
This leads to the next point you bring up, the name of Jesus. God already was named in the Old Testament and his name is YHWH (I am that I am). Since I am guessing you are a KJV only person too, everywhere in the OT where it says LORD in all capitals, that is because in Hebrew it is the divine name YHWH.
What’s funny is Jesus in Hebrew is actually Yeshua (יֵשׁוּעַ) or sometimes Yehoshua (יְהוֹשֻׁעַ) which literally means YHWH is salvation. So sorry Jesus isn’t somehow the revealed name of God.
Next let’s touch on some trinitarian Bible verses. Aside from the aforementioned great commission verse in Matthew 28:19, here are some more.
2 Corinthians 13:14. This verse includes a blessing that mentions the "grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit," again explicitly mentioning all three persons.
John 1:1-5 This passage describes Jesus as the Word, stating that "the Word was with God, and the Word was God." This verse emphasizes Jesus's divine nature and his co-equality with the Father
John 10:30 Jesus declares, "I and the Father are one," further reinforcing the unity of the Godhead and the divine nature of Jesus
Hebrews 1:1-4 This passage emphasizes the supremacy of Jesus, who is the "bright reflection of God's glory and the exact representation of his being
1 Corinthians 8:6 this says there “one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.” showing the diversity and unique personhood in the Godhead
And the list goes on and on…
