How to Understand the Bible
Scripture declares that spiritual truth is understood only by the teaching of the Holy Spirit because the human mind is incapable of comprehending God's unfathomable truths. You truly understand the Bible when God teaches you, not by reading books and commentaries, or by listening to lectures and sermons. It does not matter how smart you are or how much you study - spiritual truth is spiritually understood (1 Corinthians 2:14b)*; it is not understood by your human mind.
If human minds could interpret the Bible correctly, there would be unity and agreement among Christians about what the Bible teaches. As it is, there are hundreds of divisions within Christianity, all based on different interpretations of the Bible. This is the reason it is essential to trust God alone to teach you. Not only will you understand the Bible like never before, you will also learn how to walk in faith.
Colossians 1:9b-10a ... that you may be filled with the knowledge of His will in all spiritual wisdom and understanding,  so that you will walk in a manner worthy of the Lord, ...
By simply believing what the Bible says, the Holy Spirit will open your eyes to the magnificent reality of Christ in you and you in Christ (John 14:20). The single best explanation of how to understand the Bible is found in 1 Corinthians 2. The Apostle Paul says over and over that:  human wisdom cannot understand the things of God but  the Holy Spirit will teach you. Here are some excerpts. (Full text below.)
1 Corinthians 2:10, 11b-13a, 14, 16b  For to us God revealed them through the Spirit; for the Spirit searches all things, even the depths of God.  ... Even so the thoughts of God no one knows except the Spirit of God.  Now we have received, not the spirit of the world, but the Spirit who is from God, so that we may know the things freely given to us by God,  which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, ...  But a natural man* does not accept the things of the Spirit of God; for they are foolishness to him, and he cannot understand them, because they are spiritually appraised (understood) ...  ... But we have the mind of Christ (in our born again hearts giving us the ability to understand what the Holy Spirit is teaching us).
Full Text of 1 Corinthians 2:1-16
Ephesians 1:17-18a that the God of our Lord Jesus Christ, the Father of glory, may give to you a spirit of wisdom and of revelation in the knowledge of Him.  I pray that the eyes of your heart may be enlightened, ...
Colossians 1:9 For this reason also, since the day we heard of it, we have not ceased to pray for you and to ask that you may be filled with the knowledge of His will in all spiritual wisdom and understanding,
These passages show that it is in your spirit where God teaches you. Only your inner, born again spirit has been redeemed thus far; this is the only part of you that is righteous and alive to God (Romans 8:10b), able to "hear" His teaching. Your mortal body and human mind are still dead because of sin (Romans 8:10a) and await a future redemption (Romans 8:23b); this is why you cannot understand the spiritual things of God with your mortal mind. Only as the Holy Spirit teaches you in your spirit does your human mind begin to understand what the Bible is saying; this is the renewing of your mind that transforms you (Romans 12:2).
Letting God teach you is a matter of faith. It is both very simple and impossible at the same time. God wants to teach you ...
John 14:26a But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, ...
But, there is one thing that will block any understanding of what God is teaching you: hanging onto old beliefs. If, for example, you have been taught that believers are still sinners, holding onto that belief will prevent you from hearing the Holy Spirit teach you that you are literally righteous ever since God gave you a new heart and came to live in you. You are only seeing your flawed mortal body instead of your new spirit. Rigidly hanging onto old beliefs does not take into account that Satan is the master deceiver and that he has deceived us all (Revelation 12:9). Being open to God changing your mind at any time will transform your life.
So, what is the experience of God teaching you? Often, it begins with a thought, something new. As the Holy Spirit opens up this truth, it will eventually become so obvious that you will be perplexed as to why you didn't recognize it before.
Verse by Verse Understanding of 1 Corinthians 2
In 1 Corinthians 2, the Apostle Paul clearly states that the Holy Spirit will teach you. He also states that human wisdom cannot comprehend God's spiritual truths.
The Holy Spirit Will Teach You the Bible
Human Minds Cannot Comprehend Spiritual Truths on Its Own
The Apostle Paul Did Not Rely on His Own Human Understanding
1 Corinthians 2:1-16 And when I came to you, brethren, I did not come with superiority of speech or of wisdom, proclaiming to you the testimony of God.  For I determined to know nothing among you except Jesus Christ, and Him crucified.  I was with you in weakness and in fear and in much trembling,  and my message and my preaching were not in persuasive words of wisdom, but in demonstration of the Spirit and of power,  so that your faith would not rest on the wisdom of men, but on the power of God.
 Yet we do speak wisdom among those who are mature; a wisdom, however, not of this age nor of the rulers of this age, who are passing away;  but we speak God's wisdom in a mystery, the hidden wisdom which God predestined before the ages to our glory;  the wisdom which none of the rulers of this age has understood; for if they had understood it they would not have crucified the Lord of glory;  but just as it is written, "THINGS WHICH EYE HAS NOT SEEN AND EAR HAS NOT HEARD, AND which HAVE NOT ENTERED THE HEART OF MAN, ALL THAT GOD HAS PREPARED FOR THOSE WHO LOVE HIM."  For to us God revealed them through the Spirit; for the Spirit searches all things, even the depths of God.  For who among men knows the thoughts of a man except the spirit of the man which is in him? Even so the thoughts of God no one knows except the Spirit of God.
 Now we have received, not the spirit of the world, but the Spirit who is from God, so that we may know the things freely given to us by God,  which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, combining spiritual thoughts with spiritual words.  But a natural man* does not accept the things of the Spirit of God, for they are foolishness to him; and he cannot understand them, because they are spiritually appraised.  But he who is spiritual appraises all things, yet he himself is appraised by no one.  For WHO HAS KNOWN THE MIND OF THE LORD, THAT HE WILL INSTRUCT HIM? But we have the mind of Christ.
*See note above about "natural man" in verse 14, Click Here.