What is the consequence of not believing in the trinity?

Hi everyone,
I’m someone who’s very interested in religious studies and searching for the truth. These days I’m mostly researching christian-adjacent religions, particularly LDS and Jehova’s witnesses. What they both have in common is rejection of the trinity (alongside many, many bizarre beliefs and rules). I’ve been thinking a lot about the people raised in these religions who have never truly considered that it may not be true or investigated anything else. Their belief in God and Christ is sincere, but completely misguided. What is the consequence of this, spiritually speaking?