There is a difference between objective truth and subjective truth.
Subjective truth is truth that is different for different people. I love guacamole. This is a subjective truth. No one can tell me I don’t love guacamole. It’s true that I love guacamole because I believe it is. Someone else may hate guacamole and that would be their subjective truth.
Objective truth is truth that is true no matter what anyone believes. The earth revolves around the sun. This is an objective truth. When people believed the sun revolved around the earth, they were wrong.
If Moroni really buried gold plates in the Hill Cumorah, then this is an objective truth. It can’t be true for one person and false for another. Either the plates were buried in the Hill Cumorah or they weren’t. People can believe that they were or weren’t, but there is only one truth about it. Either they were or they weren’t.
Different people interpret the facts about Mormonism differently than I do. That’s fine.
But wait! What about the spirit?
The church teaches that when someone searches, ponders, and prays, that the Holy Ghost will teach them truth of all things through spiritual feelings. What’s wrong with praying and feeling the spirit to know that the church is true? In my experience, spiritual feelings are an unreliable indicator of things that are true.
I’ve had conflicting spiritual impressions. Early in college, I fasted and prayed very intensely to know what I should study. I felt very strongly that I should pursue medicine. Due to this interest, I found a job in a hospital that would expose me to the field of medicine. During the training for this job, all my interest in pursuing medicine left me. I wanted nothing to do with it. I now had a distinct spiritual impression that I should not pursue medicine.
Why did the spirit tell me to study medicine and then tell me not to? Either the spirit was playing tricks on me for the lulz, it wasn’t the spirit at all and I was simply experiencing different thoughts and emotions at different times. Regardless, I learned that the spirit is unreliable.
Plus, people all over the world have felt the spirit that their religion is true. They experience the same feelings and share the same types of experiences when they share their testimony of their religion. Muslims know their religion is true and that Muhammed is God’s last prophet. Catholics know their church has the true Priesthood authority. And on and on. Not every religion claims to be the one true religion on earth, but many do. And all these true religions teach fundamentally incompatible things. They can’t all be true.
But if the spirit is unreliable, what can we do?
People often use different phrases to express why they feel or think certain things. You’ve certainly heard the phrases “I have a gut feeling that…” or “my heart is telling me…” or “I think that…”
I have a gut. I have a heart. I have a brain. If something went wrong with my gut and it was replaced, I’d still be me. If something went wrong with my heart and it was replaced, I’d still be me. But if something went wrong with my brain and it was replaced (pretending such a thing was possible) I wouldn’t be me anymore. While I do believe in a mind/body connection, at the end of the day what makes me me is the brain inside my head and everything stored there. If you took out my brain and replaced it with a different one that had different things stored in it, I wouldn’t be me anymore.
When faced with determining what to believe, I listen to my brain first. I know my brain can lead me astray. So can my heart. So can my gut. But as wrong as my brain can be, I trust it the most. I do my best to think, evaluate the evidence, and draw conclusions that make sense to me while always remembering that I’m human and could be wrong.