Because of this, God sends them a working of error, that they should believe a lie WEB
“Because of this” Meaning, for rejecting the truth as revealed in God’s Word.
“God sends them” God allows the devil to deceive those who actually chose deception by rejecting Jesus Christ, who alone opens the eyes to know the truth to those who believe in Him.
Without the Holy Spirit guiding a person into the truth, they will believe any lie hurled at them by the enemy.
Insight: Working of Error
The phrase Working of error or a strong delusion, suggests as the Greek word Working means a “superhuman activity” (demonic spirits) which involves a deception that is not from this world.