I grew up believing that God told you what was true through his Holy Spirit, and you felt that spirit through feelings and emotions. When I was a missionary, we taught people that when they felt a peaceful, warm, or good feeling, that was the Holy Ghost testifying that what we were teaching was true. Apostle Henry Eyring says much the same thing when he teaches about how to recognize the spirit:
You have felt the quiet confirmation in your heart and mind that something was true. And you knew that it was inspiration from God. For some of you it may have come as the missionaries taught you before your baptism. It may have come during a talk, lesson, or hymn in church. The Holy Ghost is the Spirit of Truth. You feel peace, hope, and joy when He speaks to your heart and mind that something is true. Almost always I have also felt a sensation of light. Any feeling I may have had of darkness is dispelled, and my desire to do right grows.
This worked for me for a long time until I discovered that some of the things the spirit had testified of just weren’t true. And some of those things were morally wrong. I wondered why God would testify of such things, and I concluded that he must not exist, or must not care about me at all. I still believe in God, but it has taken time to get over the hurt and anger I felt toward Him.