In the 21st century where so much of our information can be fed to us by algorithms and marketing ploys, growing in the ability to spiritually discern is very important as disciples.
I don't remember when I first heard the expression, "eat the meat and leave the bones", but I have found it is a very helpful concept in my spiritual life. Typically the phrase simply means to take the good, and leave the bad. Anyone who has been a Christian for longer than a year (or maybe even two weeks!) knows that there are a lot of things that the bible doesn't seem to give us black and white instruction on, and while there are many biblical principles that can be applied to much of life, we find ourselves navigating in the grey perhaps more than we like to admit.
It is in this reality and context that I believe this 'eating the meat and leaving the bones' concept is most helpful. One of the marks of spiritual maturity is the ability to feed and train oneself spiritually (Heb 5:14; 1 Tim 4:7). In order to do this you must be able to discern what the "meat" is, and what the "bones" are.
The Meat
I would describe the "meat" as that which is helpful, beneficial, and not in conflict with the revealed will of God through his word. If you are not able to discern what is in conflict with the word of God and what is not, then obviously you are not in a position to "eat the meat" of some other persons ideas (whether they be in a book, conference, podcast, or some other form of communication). So if you do not know the word well enough to have a grasp of the major doctrines and ideas therein, that would be exactly where you need to start (a good place to start with this is to make is a goal to read the bible each year - this takes discipline and perseverance, but ultimately I believe ones devotion to the word of God, and their application of it, reveals their belief in whether it is truly divine).
The Bones
I would describe the "bones" as that which is not helpful, beneficial, or perhaps that which is even in conflict with the word of God. Again, you cannot leave the bones, unless you are in a position to at least identify what the bones could be. Once you are able to recognize what the bones are, then you simply leave them on the plate and move one, not allowing them to taint for you the wonderful taste of the meat that is good.
Can You Eat Discernibly?
We run into situations all the time where we are forced to choose what we think about something. For instance, take your typical Sunday church service experience: do you believe everything you see, hear, and experience there? If you are not swallowing everything "hook, line, and sinker", than how are you making your judgments and decisions? There comes your ability to discern. We all do this all the time, but for many of us we are not aware that we are doing it, and worse yet, we aren't aware of why and how we are doing it. If you never develop the ability to discern, you stay spiritually immature, and ultimately must rely on someone else to teach you the elementary truths of God (Heb 5:12), not to mention you are more predisposed to being a doubting wave of the sea tossed back and forth by the wind (Jam 1:6).
As an example, are you able to put yourself in a position to learn from someone that doesn't agree with you in every area? Could you read the classic Confessions by St. Augustine even though you likely don't agree on every doctrinal point (perhaps even some that you believe are vital) and still be able to get something out of it? Or could you read a book, listen to a sermon, or attend a conference with John Piper, Francis Chan, David Platt or Bobby Harrington (perhaps even this article itself) and not feel like you are subjecting yourself to "spiritual pornography"? (Yes, I have actually heard of such things referred to this way). Hopefully as a disciple of Jesus Christ, you are dedicated to being a lifelong learner, and your ability to discern, much less how you feel about this process, ultimately comes down to your spiritual maturity and understanding, your ability to "eat the meat and leave the bones".