Vitamins and supplements are good, right? They can be, but can you imagine supplementing your entire diet with vitamins? Like, not eating any food, but only taking vitamins! That would be super unhealthy, right (and kinda crazy)?! Of course, vitamins are good, but we need food.
Well, what about our spiritual diet? Reading devotions, commentaries, listening to Christian podcasts, etc. are all good, right? But what if you're substituting all of these instead of having time in the pure word of God? That's also unhealthy. Sure, all those things are good and can add to our Christian walk, but we need the Bible. The pure, unadulterated word of God.
In Deuteronomy 8:3 it is written, (and then reiterated by Jesus later) that man shall not live by bread alone; but man lives by every word that proceeds from the mouth of the Lord. This shows us how vital God's word is to the believer. We would never neglect or forget to feed our physical body, so how much more should we never neglect to feed our spirit.
Also in Jeremiah 31:34 it says, "No more shall every man teach his neighbor, and every man his brother, saying, ‘Know the Lord,’ for they all shall know Me, from the least of them to the greatest of them, says the Lord." This scripture is so awesome because we, as born again believers, don't need anyone to reveal who the Father is. God desires to meet with His children one on one to reveal Himself to them through His Spirit. Sure fellowship is blessed and our iron can really be sharpened by those who are deep in their walk with Jesus, but nothing could or should substitute what only God can reveal Himself to the individual. Remember in John 1:1 Jesus is called the Word. So when we are ingesting the word into our spirit we are ingesting Jesus. Awesome, right!
So, while devotions and books and commentaries are helpful, they aren't necessary to knowing the Lord. I would encourage you to read your word every day and add those other things like you would a supplement.
Love and God bless,
Akiko