Colossians 1:15 KJV
Who is the image of the invisible God, the firstborn of every creature:
2 Corinthians 4:5-6 KJV
For we preach not ourselves, but Christ Jesus the Lord; and ourselves your servants for Jesus’ sake.  For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ.
Spiritual blindness is a grievous condition experienced by those who do not believe in God, Jesus Christ, and His Word.
Romans 2:8 But unto them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath,
Romans 2:9 Tribulation and anguish, upon every soul of man that doeth evil, of the Jew first, and also of the Gentile;
2 Thessalonians 2:8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
2 Thessalonians 2:9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
Those who reject Christ are the lost.
John 6:68 KJV Then Simon Peter answered him, Lord, to whom shall we go? thou hast the words of eternal life.
John 6:69 KJV And we believe and are sure that thou art that Christ, the Son of the living God.
Being spiritually blind, they are perishing (2 Corinthians 4:3-4; Revelation 3:17).
They choose not to accept the teachings of Christ and His authority in their lives (Matthew 28:18).
They are blind to the manifestations of God as revealed throughout His Word and Jesus Christ (John 1:1; Acts 28:26-27).
They are described as those who “do not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned” (1 Corinthians 2:14).
Peter spoke of such people as “scoffers [who] will come in the last days with scoffing, following their own sinful desires” (2 Peter 3:3; see also Proverbs 21:24; Jude 1:18).
Those who reject Christ and His Word are spiritually blind and cannot understand the truth of the Scriptures. The truth sounds foolish to them (Isaiah 5:25; Isaiah 37:23).
The Bible describes those denying God as fools (Psalm 14:1; Matthew 7:26).
Because of their blindness and rejection of God and His Word, they are in a perilous, unsaved condition (John 12:48; Hebrews 2:2-4).
The spiritually blind are simply unable to understand God’s Word (Matthew 13:13; Deuteronomy 29:4).
Jesus said, “If you love Me, you will keep My commandments. And I will ask the Father, and He will give you another Helper, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees Him nor knows Him. You know Him, for He dwells with you and will be in you” (John 14:15-17).
Paul echoed this when he told the believers in Rome, “Those who are in the flesh cannot please God. You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to Him” (Romans 8:8-9).
Those outside of Christ are not of God because their lives are steeped in the things of the world with all its passions, their eyes blind to the Spirit of God. The Apostle John said, “If anyone loves the world, the love of the Father is not in him” but that person’s love “is from the world” (1 John 2:15-16).
The cause of spiritual blindness is made quite clear in the Scriptures: “In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God” (2 Corinthians 4:4).
Paul refers to Satan as the “god of this world.” Extraordinarily evil (John 8:44), Satan destroys the flesh (1 Corinthians 5:5), masquerades as an angel of light (2 Corinthians 11:14), and is the cause of all temptations (Luke 4:2; Hebrews 4:15; 1 Corinthians 7:5). He revels in scheming against and trapping the unbelievers (2 Corinthians 2:11; Ephesians 6:11; 2 Timothy 2:26).
Satan’s goal is to devour the weak who fall prey to temptation, fear, loneliness, worry, depression, and persecution (1 Peter 5:8-9).
Without God and left to ourselves, we easily succumb to the devil’s schemes. We can become so mired in the affairs of this world and its moral darkness that, in the end, God turns us over to spiritual blindness and eternal condemnation (John 12:40; Romans 1:24-32).
As believers, we have the Spirit of God reigning in our lives to ward off the debilitating effects of Satan’s power and the world’s influence (1 John 4:13).
John tells us, “Whoever confesses that Jesus is the Son of God, God abides in Him, and he in God” (1 John 4:15). Satan wars within and without us. His weapons are deceitful and crafty schemes to make us doubt and stumble (2 Corinthians 2:11; Ephesians 4:14). Yet God has provided us with powerful weapons to ward off his flaming arrows (Ephesians 6:10-18). As believers we can overcome the evil one and remain in the Light and never become spiritually blind. For, in truth, Jesus has given us His wonderful promise: “I am the light of the world. Whoever follows Me will not walk in darkness, but will have the light of life” (John 8:12).