Man has increased in scientific, medical, historical, educational, psychological, and technological knowledge to an astounding degree. But he has not changed his own basic nature and he has not improved society.
Man’s knowledge has greatly improved, but his morals have progressively degenerated. His confidence has increased, but his peace of mind has diminished. His accomplishments have increased, but his sense of purpose and meaning have all but disappeared.
Instead of improving the moral and spiritual quality of his life, man’s discoveries and accomplishments have simply provided ways for him to express and promote his depravity faster and more destructively.
Modern man has simply invented more ways to corrupt and destroy himself.
Man’s knowledge is increasing by quantum leaps, but his increased knowledge is mechanical knowledge, inanimate knowledge, lifeless knowledge, knowledge that has no bearing on the inner man (cf. 2Tim. 3:7). His knowledge does not retard his corruption but rather is used to intensify and defend it.
The MacArthur New Testament Commentary by John MacArthur
Matthew 1-7 Page 238
As God’s children and as the temples of His Holy Spirit, Christians represent God’s presence in the earth. We are the salt that prevents the entire earth from degenerating even faster than it is.
The MacArthur New Testament Commentary by John MacArthur
Matthew 1-7 Page 243
“You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled by men.”
Matthew 5:13