To be blind means one can't see clearly where they are and where they are going. Thus they stumble along as best they can.
Spiritual blindness is much the same.
The Laodicean church has a bad case of blindness. They think they are rich and increased with goods, in need of nothing. BUT they are blind, poor, wretched and miserable and can't see it.
Possibly the cause of blindness is failure to hear or grasp the basic fundamental points of the gospel.
The first step in understanding the gospel is to recognize one's need. Blindness with a big case of unbelief?
Unbelief. Hebrews 3 tells us people missed out on entering the "rest" because of unbelief. Unbelief is not necessarily saying there is no God; rather, unbelief is a willful rejection of God and His Law, while still engaging in formal rituals Someone can be blind to their unbelief because they believe there is a God somewhere, way out there, and as long as they live half decent lives they'll make out O.K.
The world is eager to shrug off God's commandments and redefine sin, or do away with the concept of sin altogether. With a "whatever's right for you, is right" attitude.
The blindness that hides our greatest need, is the worst blindness to spiritual life.
God's law is as true and binding as it was 2000 years ago. And we've broken that law! We are guilty of high treason against the kingdom of God! We've sold out to the arch enemy of Christ. And the penalty for treason is eternal death. We take our condition lightly, blinded by the philosophies of the world. But sinners must see their offensive condition, rebels against God, with sin separating them from God. Only then can the Holy Spirit get through to their minds and convict sinners of their sinfulness and the serious end result of sinful life habit's that separate them from God.
Only then can we see the value of the gospel. Salvation comes from a gracious God who offers us deliverance from our pitiful state. When the sinner acknowledges their sin and repents from their sin of unbelief and turns to Christ by faith, they understand that God's work of salvation is wholly dependent and fulfilled only in the atoning work of Jesus Christ at the cross.
. It is the good news that Jesus Christ willingly died for our sins, was buried and was bodily raised by God from the grave. To understand that the gospel of Jesus Christ is the only path of salvation. The gospel is God's demonstration of both grace and justice. Christ willingly died for all our sins (Romans 5:8). In His death, Christ became our substitute, literally, He took our place as He bore God's judgment for our treason. He bore it on our behalf, and suffered a cruel, criminal's death. Thus, salvation is by grace, known as unmerited favor; but not without justice. Jesus was judged in our stead. At the cross, Jesus laid down his life willingly for all.
But that's not the end. Who are we going to be loyal to now. Romans 6 tells us we are the servants of the one we obey. Why would we want to continue in a life of treason against the One Who took our place, and died. Once our spiritual eyesight is enlightened, we abhor the deceitfulness and evil of sin.
Yet we can't be holy in our own strength. Only God is truly holy, and the only way we can rise above the sinful habits that have plagued us for years, is to be very close to Jesus.
And when our eyes have been washed with tears of gratitude for our Saviour's awesome provision for our salvation, we want to be led by the Holy Spirit, live by the Spirit, not the flesh, and rely exclusively on God's Word, in trust and obedience.
A spiritual blind person stumbles along in their own strength and wisdom thinking they are doing just fine. But God wants them to open their eyes and see the deployable state they are in and come to HIM who has things for them they haven't even dreamed of -- so great and wonderful.