The reason why a person might not understand the Bible depends on a number of things. However, there are two main reasons that I have come to realize why a person will not understand the Bible, apart from not understanding the actual language that is used.
The first reason I found that restricts our understanding to learn a new idea is unless we are ready to grasp what the idea means and utilize it to our own benefit in a meaningful way, we will fail to understand it. For instance, when it comes to being able to comprehend a written language, we first need to understand the alphabet, then what the basic words mean. These are single syllable words. In English these are words like look, hear, love, good, bad, live, dead, book, stand, and then on to two syllable words such as “under”, which, with the word “stand”, goes to form, “understand”. The word “under” means to “be below something” or “in a lower position” and “stand” means to be “upright on feet”. The word “understand” then means, “to stand upright but in a lower position in relation to something else”. From a biblical perspective this suggests taking a stand against men and calling upon the name of the Lord God Almighty, Creator of Heaven and Earth. Implicit in the word “understand” is the idea that we have to first make a declaration and say, “I do not know what something means and I desire to know”. This requires us to cast aside our preconceptions or opinions and see ourselves somewhat lower in status than what we might like to assume. This means we need to be willing to listen to ideas until we are able to understand what the person is saying so that we can arrive at truth. This also means that we need to look at something until we can recognize the object as distinct from other objects, or we can grasp an idea in our mind as distinct from other ideas. We cannot afford to allow preconceptions get in the way of learning the truth of a matter—unfortunately, there are many, who are opinionated, whom the book of wisdom calls fools, because they jump to conclusions or interpret from preconceptions frequently—and miss the truth. If someone says to us that the Bible is the written Word of God and has some essential information about life and the reason we exist, it is only natural we should investigate what it says on the basis that this is so.
However, assuming we approach the Bible with the view that we have the answers about life and we think we know something, we have automatically invalidated the reason why we might be seeking to understand what the written Word of God has to say that might have significance for us. Consequently, we are not going to be able to understand what we read in Bible. The way the Bible has been written is such that only people who are genuinely looking for the truth will learn what it has for them. To this effect, Jesus said that if we continue seeking to understand His words and apply them in our lives, we could know the truth and discover freedom to do more with our lives than what we otherwise would have known. This is why many people quote the words of the Bible. There is much wisdom in the Bible, only wisdom comes from applied knowledge and not theoretical knowledge.
Many people have the intellectual capability to comprehend numerous philosophies concocted to explain life and the jargon used by philosophers, but the inability to understand truth, because they are too foolish to seek wisdom and live authentically in its truth. By authentically living our lives in truth, we are able to understand what the Bible states and we will learn more wisdom as we grow in the knowledge written therein.
The Bible is written in parables and seeming nonsense so that the opinionated (those who think they are wiser than the Omniscient Creator and have no need to acknowledge Him) do not learn the truths contained within. God tests us to see whether we genuinely want to know the truth or whether we are going to get our rocks off thinking, we are smarter than others are, because we can regurgitate information and the opinions of other people that we have read in books. If we are humble, we will call upon God and ask Him to help us.
The Bible informs us to call upon the name of God, which is Lord Jesus Christ. Lord Jesus Christ is the revealed name of God, and under this name; we are to glorify our Heavenly Father. This being the case, we speak to God in the name of Lord Jesus and ask Him to help us. This is what the Bible states:
And without faith it is impossible to please him. For whoever would draw near to God must believe that he exists and that he rewards those who seek him. (Hebrews 11:6 RSV)
Unless you believe God exists, you will not call upon Him. If you believe God exists, you will call upon Him, which is an act of faith if you expect God to reward you. If you do not expect God to reward you, or even to hear you, you will be like the fools who say He does not exist, so I will not call upon Him. If you believe God exists, you will wait until you receive your answer. So if you ask our Heavenly Father in the name of Lord Jesus Christ to reveal you the truth, faith is evidenced, when you wait until you receive the answer to your query (prayer).
The second reason people do not understand the Bible is that they do not have the Holy Spirit. Many people attempt to work out what the Bible means without the Holy Spirit. Instead of learning truth, they are caught up in religious dogma, which are doctrines of the men (the Devil really) that prevent people from discovering the reality of a personal experience with Lord Jesus Christ in the power of the Holy Spirit. This is what Jesus actually stated regarding the Holy Spirit:
“If you love me, you will keep my commandments. And I will pray the Father, and he will give you another Counselor, to be with you for ever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him; you know him, for he dwells with you, and will be in you. (John 14:15-17)
But when the Counselor comes, whom I shall send to you from the Father, even the Spirit of truth, who proceeds from the Father, he will bear witness to me. (John 15:26)
When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He will glorify me, for he will take what is mine and declare it to you. All that the Father has is mine; therefore I said that he will take what is mine and declare it to you. (John 16:13-15 RSV)
As you can see, from the above Scripture, the Holy Spirit is given so that people are guided into knowing the truth. What this means is that Holy Spirit will give us understanding of what we need to know as we read the Bible. However, notice the first sentence of what Jesus said. There is a qualifying criterion to receiving the Holy Spirit. If we love Jesus, we will keep His commandments and He will pray the Father to give us another Counselor, Who is the Holy Spirit.
One of the reasons people do not understand the Scriptures is they have not seen reason to love Lord Jesus because they do not appreciate what He has done for them.
We could say not knowing our need for Jesus Christ to be our Savoir and Lord is the underlying reason people do not come to understand what the Bible really says, and why there are so many different views regarding what is required of us, if we are to know the truth. Unless we understand why we would want to call upon the Lord God in the first place, we will not really be seeking the truth.
Opinions, thought bubbles, philosophy, doctrines, esoteric information from the occult, are ploys used by the god of this world to deceive us, if we do not truly understand why we want to know Lord Jesus Christ; the only person to have risen from the dead, and Who reveals Himself to those whose hearts are pure and their motives genuine.
Another reason why people do not understand the Bible is because they do not understand the only words that were written by God Himself. The majority of people who call themselves Christians arrogantly dismiss them and those that claim they know them, actually cannot even quote them. So how can they know them.
Just to show you have ignorant people are, if you ask them whether the Bible states the Son of God actually delivered the Ten Commandments to Moses, they will most likely say, "No!" The truth is the Son of God (through Whom all things exist) did deliver the Ten Commandments to Moses . Furthermore, Jesus, the Son of God said, "Heaven and Earth will pass away, but not one dot nor one iota of the Law shall pass away until all is accomplished."
Yet Jesus says if you continue in my commandments I will send the Counselor and He will lead you into all truth.
What it all boils down to, in the end, is how much do we want to know the truth. Or are we content to settle for less and play philosophical mind games rather than experience a relationship with our Heavenly Father through Lord Jesus Christ in the power of the Holy Spirit.