What Is a Testimony?

Many people who have left the LDS faith seem to struggle with the concept of a testimony, revelation, and what it means to feel the Spirit.
I wonder if there are some within the Church who have the same struggle.
I give a few of my insights and experiences, and share tow talks that have helped me in my understanding.

Testimony – Elder Gordon B Hinckley Apr ‘98
Candle of the Lord – Elder Boyd K Packer Jan ‘83