Whoso would hearken unto the word of God, and would hold fast unto it, they would never perish; neither could the temptations and the fiery darts of the adversary overpower them unto blindness, to lead them away to destruction.
1 Nephi 15:24
"Holding fast” to the word of God means a lot more than occasional reading. It means internalizing it, making it a part of the very fiber of our beings.
To accomplish this requires repetition—frequent and continual repetition. Over and over we must run the promises through our minds until that spiritual current, as it were, reprograms or repolarizes our thought patterns so that the brain is prepared to accept a new way of thinking about our problems and our faith in Christ’s power to solve those problems.
- Steven A. Cramer, “Armed With Righteousness”

My thought yesterday was about strengthening the armor that we wear to protect us on the inside, protecting our souls, from the fiery darts of Satan. One sure way of strengthening that armor is to "hold fast" to the word of God. We have to internalize the truths and promises in the scriptures. We need to search the scriptures in order to know what those promises are.
We must internalize the word of God. Frequently. Over and over. Continually. Then repeat. Those truths and promises need to occupy our thoughts. When we are not intentionally focused elsewhere, like parenting, school, work, etc., it has to be second nature for our minds and thoughts to default to the word of God. Not wander. Not be idol. I try to memorize scriptures and then recite them over and over in my head. I try to memorize my blessing and recite that.