The basic definition of doctrine is "a belief or set of beliefs held and taught by a church, political party, or other group."
Taking that definition then, each of us functions on the basis of doctrine. We all hold to certain beliefs, and those beliefs impact the way we live. The questions to consider, then, are:
Am I living the way I say I believe?
Is what I believe true to the Word of God? Is it 'sound doctrine'?
Is what I read, listen to, and immerse myself in accord with sound doctrine?
Nancy DeMoss brings up an excellent point in her devotional, The Quiet Place: "How many people do you know who go to great lengths to ensure the safety and soundness of the foods they eat? And yet how many people do you know are are just as careful to guard their hearts and minds from belief systems that can weaken their whole outlook on life and faithful performance of their duties in the home, the workplace, and even in their local church or ministry?"
The difficult thing is, while there is a lot of obvious false doctrine, there is a lot of doctrine that is just slightly off that seems right at the out-set. It isn't until we thoroughly search and study that we can really determine what is true.
"Outright false doctrine isn't that hard to spot or avoid....What we must be careful about is letting our spiritual intake become sprinkled with just enough error, dispensed by charismatic personalities with just enough emotional stories and funny jokes, causing us to end up believing things that slowly deaden our spiritual senses over time." Nancy DeMoss
Have you thought that doctrine isn't that necessary? Then I ask you to reconsider.
"Maybe you’ve never thought about it in these terms, but coming to Jesus and listening to his words involves doctrine. It involves knowing and understanding what the Bible teaches about who Jesus is, why we need him, how he saves us and changes us. In other words, it involves knowing theological truth." Joshua Harris, Dug Down Deep
But of course, the truth alone is never enough if it doesn't impact and change our hearts.
"If doctrine is only words on a page, it can be perceived as a bunch of lifeless rules or formulas. But when you see orthodoxy in the vibrant colors of a person’s life—when you observe that person applying it with joy and humility—you see that it’s beautiful." Joshua Harris
We need to realize that answering the question about doctrine is an issue we need to be prepared to face.
"As for you, teach what accords with sound doctrine..." Titus 2:1