1. Impurity:
Impurity enters into our hearts mainly through our eyes and our ears. This impurity then comes out from our hearts and expresses itself through the various members of our bodies - primarily through our tongues and our eyes. Anyone who seeks to be pure must therefore be especially careful about what he sees and what he hears. Jesus hated impurity so much that He told His disciples that they should be willing to pluck out their right eye and cut off their right hand rather than sin with those members (Matt. 5:27-29).
When do doctors recommend the amputation of the right hand or the surgical removal of an eye? Only when things have become so bad that without the removal of these organs, the whole body will die. This is what we need to understand in relation to sin as well. Sin is so serious that it can imperil our very life. Most believers have not realized this and that is why they are careless in the way they use their tongues and their eyes. We must be as blind men and as dumb men when tempted to sin with our eyes and our tongues. This is the implication of Jesus' words.
2. Unbelief:
The Bible speaks of an unbelieving heart as an EVIL heart (Heb. 3:12) Jesus rebuked His disciples seven times for unbelief. (See Matt.6:30; 8:26; 14:31;16:8; 17:17-20; Mark.16:14; Lk.24:25). It seems that He almost never rebuked His disciples for anything else!! Unbelief is an insult to God, because it implies that God does not care or provide for His children even as much as evil fathers on earth care and provide for their children. There is also a counterfeit faith being preached these days, as a means of getting things from God. But that is not the faith that Jesus preached. He wanted us to have faith to live by, in our daily life. Victory over depression, bad moods and discouragement can come only as we have faith in a loving Father in heaven and in the wonderful promises He has given us in His Word. Twice we read of Jesus being amazed - once when he saw FAITH and once when He saw UNBELIEF!!(Matt.8:10; Mark.6:6).
Jesus was excited whenever He saw faith in people. And He was disappointed when He saw people unwilling to trust in a loving Father in heaven.
3. Spiritual Pride:
Spiritual pride is the most common sin to be found among those who pursue after holiness. We all know the parable of the self-righteous Pharisee who despised others even in his prayer (Luke. 18:9-14)! It is more than likely that 90% of all prayers offered in public by believers are primarily meant to impress others who are listening and not prayed to God at all. The Pharisee in the parable may not have been evil like other sinners in his external life. But Jesus hated the pride with which he thought of his spiritual activities and with which he despised others. It is spiritual pride that makes believers constantly judge other believers.
The tax collector however, who saw himself as THE sinner - worse than all others - was accepted by God. All who have come face to face with God will have seen themselves at some time, as the chief of sinners.
Jesus taught that the greatest person in heaven would be the humblest (Matt. 18:4). The greatest virtue found in heaven is humility. We see in the book of Revelation that all those who receive crowns in heaven are quick to cast them down before the Lord acknowledging that He alone deserves every crown (Rev. 4:10, 11).
Jesus said that even if we managed to obey EVERY SINGLE commandment of God, we would still be unprofitable servants who have not done anything more than what was expected of us (Luke. 17:10). Then what shall we say about our condition when we fall so often!