Warm greetings to my dear brothers of 
When a person has not yet let Jesus enter his heart to dwell in him, he is spiritually blind, his physical eyes can see everything that surrounds him in the physical world but not in the spiritual world, and when a person does not it can see spiritually, it is tied because it can not be guided by itself; this is what happens to the world today and that makes it roll from one place to another in search of solutions to problems but without too much success.
Many times people will preach on the streets and people will be told to come to Christ and their lives will change, and in many cases people come to church but time passes and their lives do not change. Why? Because they remain spiritually blind because they do not allow GOD to guide them in that new life, assuming their own guidance, while the Bible says that if a blind man leads a blind man, both will fall into the well.
It is said that "there is no worse blind than the one who does not want to see, nor worse deaf than the one who does not want to hear", and I think that this is precisely the case of those who do not want to see the reality of their lives, because there it is. the truth, in the facts, and that is what happens to those who like the Pharisees, who, seeing, did not want to recognize the miracle that Jesus Christ did; the doctrine with which they were educated closed their eyes, and there are many to whom the enemy does not allow them to see the miracle that Jesus has done in their lives and that they come from God.
The Bible says in John 9: 35-41
"Jesus heard that he had been expelled; and finding him, he said to him: Do you believe in the Son of God? He answered and said: Who is it, Lord, to believe in him? Jesus said to him, "You have seen him, and he who speaks with you, he is." And he said: I believe, Lord; and he adored him. Jesus said: For judgment I have come to this world; so that those who do not see, see, and those who see, are blinded. Then some of the Pharisees who were with him, on hearing this, said to him: Are we also blind? Jesus answered them: If you were blind, you would not have sin; But now, because you say: We see, your sin remains".
When we do not understand spiritual things it is a main sign of blindness, and when we do not see the miracles that GOD did and continue to do, therefore, all biblical relationships are interrupted, we do not want to read the Bible, we do not want to congregate, and especially when We look for any excuse to make room for carnal things. This way of leading a life can generate a spiritual sterility that does not allow us to bear fruit, then we fall into a stalemate that does not even allow us to see the spiritual danger, because "The wise see evil and move away; But the simple pass and receive the damage". Proverbs 22: 3.
The enemy uses spiritual blindness so that we lose sight of the love of God that has been poured out on our lives, and we stop valuing the received supernatural blessings; and one way to keep us blind spiritual is through disbelief, not having faith.
Thanks to the spiritual blindness caused by unbelief there are those who fail to see the supernatural that God has done in their lives, such as healing, liberation, prophecy, gift, talent, ministry, blessing, and all the things the Lord has done. in us even when we do not deserve it.
Jesus tells us: "Do you not believe that I am in the Father, and the Father in me? The words that I speak to you, I do not speak on my own, but the Father who dwells in me, he does the works. Believe me that I am in the Father, and the Father in me; otherwise, believe me for the same works. Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and even greater will he do, because I go to the Father. And whatever you ask of the Father in my name, I will do it, so that the Father may be glorified in the Son. If you ask anything in my name, I will do it".John 14: 10-14.