1 Corinthians 2:13 Which things also we speak, not in the words which man’s wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.
14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
These verses are telling us that the things we speak are those things which only the Holy Ghost can teach us. People who read the Bible and do not understand it do not have their focus on The Holy Spirit and that is why they can not understand. To be able to comprehend what the Spirit is saying we have to combine spiritual things with spiritual words. He goes to let us know that the natural man only looks at the world with a canal mind. The physical man believes only what he can see, touch, or taste because the Spirit does not dwell in him and the things of God are foolish to him. As spiritual discernment is generated only by the Holy Spirit then the capacity to know spiritual truth is beyond the innate powers of the natural man. The natural man lacks the ability to discern the facts God. This last group is the ones we need to be reaching to, to help them find what the Holy Spirit can do for them.