Certainly there are some passages in which a...spiritual understanding is necessary for the passage to make sense. However: the Bible is a very advanced work of ancient, foreign literature. Far more often than a lack of spiritual insight, a lack of education in grammar and vocabulary results in misunderstanding the Bible. This is especially true of the King James Version, which uses a very early form of Modern English. That is: an archaic form of the English language that is in many particulars no longer in use. The great majority of English speakers are not fluent in that language and the great majority of KJV readers make no effort to become fluent in that language, and thus the great majority of KJV readers fail to correctly understand many passages.

He that hath an ear, let him hear what the Spirit saith unto the churches.

Yes, I believe so

The Bible is meant for everyone's level of understanding. The better educated can read the deeper contexts that are contained within. But even if it's only the 10 Commandments that you understand, you have basically all you need to lead a decent and moral life.

The scriptures are a spiritual teaching, leading to eternal life in the spirit, hence they are not only to be read with reasoning but with the spirit. 2 timothy 3:16 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, John 5:39-40 You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me, yet you refuse to come to me that you may have life. John 3:6 That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Luke 24 :44-45 Jesus said to them, “These are the words I spoke to you while I was still with you: Everything must be fulfilled that is written about Me in the Law of Moses, the Prophets, and the Psalms.” Then He opened their minds to understand the Scriptures. John 16:13 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. Matthew 11:25 At that time Jesus declared, “I thank you, Father, Lord of heaven and earth, that you have hidden these things from the wise and understanding and revealed them to little children; Psalms 119 Blessed are those whose way is blameless, who walk in the law of the Lord! Blessed are those who keep his testimonies, who seek him with their whole heart, who also do no wrong, but walk in his ways! You have commanded your precepts to be kept diligently. Oh that my ways may be steadfast in keeping your statutes! ...