While the word ‘disbelief’ is not found in God’s Word, I assume you are referring to ‘unbelief’ or ‘unbelievers’. Let’s read 2 Corinthians 6:14, “Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?” The Greek word for unbeliever is ‘apistos’ and means to be without Christian faith, faithless, disbelieving. This same Greek word is also translated:

  • FAITHLESS in Matthew 17:17.
  • BELIEVETH NOT in 1 Corinthians 7:12.
  • UNBELIEVING in 1 Corinthians 7:15.
  • INFIDEL in 2 Corinthians 6:15.

There is a dire warning to unbelievers in 2 Thessalonians 1:7-9, “…the Lord Jesus shall be revealed from heaven with his mighty angels, In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ: Who shall be PUNISHED WITH EVERLASTING DESTRUCTION from the presence of the Lord, and from the glory of his power.” To those who reject the grace of the Lord Jesus, who refuse to obey the gospel, there is only EVERLASTING DESTRUCTION to look forward to. What is the Gospel that must be obeyed? Acts 16:31, “BELIEVE on the Lord Jesus Christ, and thou shalt be saved…” Romans 10:9, “That if thou shalt confess with thy mouth the Lord Jesus, and shalt BELIEVE in thine heart that God hath raised him from the dead, thou shalt be saved.” To be saved, you must believe that God’s Son, the Lord Jesus Christ died for your sins and was raised again the third day. Do you believe or are you an unbeliever? Scripture speaks of Hell as a place where those there “shall be tormented day and night for ever and ever.” (Revelation 20:10) If you have not, put your faith in the Lord Jesus Christ and avoid this terrible place of eternal punishment. (238.6)

Unbelief is the opposite of faith. Faith is taking God at His word, while unbelief does not believe what God has said. We read in Hebrews 11:6, “But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.” Faith in the Lord is needed for salvation. Ephesians 2:8 says, “For by grace are ye saved through FAITH…” Jesus said in Mark 11:22, “Have FAITH in God.” Romans 5:1 says, “Therefore being justified by FAITH, we have peace with God through our Lord Jesus Christ.” In the New Testament, we find the word ‘FAITH’ 245 times. That should indicate its importance!

From the use of this word, we can see that an unbeliever is one who has refused to take God at His Word. He is an infidel. He distrusts or rejects God. This is a sin that will lead one to Hell. John 3:18 warns us, “He that believeth on him is not condemned: but he HE THAT BELIEVETH NOT IS CONDEMNED ALREADY, because he hath not believed in the name of the only begotten Son of God.”