The Bible says in 1 Peter 4:4, Wherein they think it strange that ye run not with them to the same excess of riot, speaking evil of you:
The world doesn’t understand why we no longer want to run with them anymore. I like what Wiersbe said, “They do not think it strange when people wreck their bodies, destroy their homes, and ruin their lives by running from one sin to another! But let a drunkard become sober, or an immoral person pure, and the family thinks he has lost his mind!”
Festus told Paul in Acts 26:24, Paul, you are out of your mind! Your great learning is driving you mad.
They said of Jesus in Mark 3:21, When His own people heard of this, they went out to take custody of Him; for they were saying, "He has lost His senses.
In truth, the unsaved man is spiritually blind to the truth. Paul said in 2 Cor. 4:3-4 And even if our gospel is veiled, it is veiled to those who are perishing, (4) in whose case the god of this world has blinded the minds of the unbelieving so that they might not see the light of the gospel of the glory of Christ, who is the image of God.
Also in 1 Cor. 2:14-15 But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned. (15) But he who is spiritual judges all things, yet he himself is rightly judged by no one.