1. Know that Jesus said, "What comes out of a man is what makes him unclean. For from within, out of men's hearts, come evil thoughts, sexual immorality, theft, murder, adultery, greed, malice, deceit, lewdness, envy, slander, arrogance, and folly." (Mark 7:20,21) Every outward act of sin is proceeded by an inward act of choice. Therefore, Jesus addresses the root cause of man's worst problem - sin. Sin is missing the mark of God's holiness in our character, thinking and actions. Sin is like a thief - it seeks to kill, slaughter, steal and destroy. (Jn. 10:10) Sin is unclean like pigs - 2 Pet 2:22 says, "Of them the proverbs are true; 'A dog returns to it vomit" and 'A sow that is washed goes back to her wallowing in the mud." Sin is like a cancer as it destroys from within. James 4:1,2 says, "What causes fights and quarrels among you? Don't they come from your desires that battle within you? You want something but don't get it so you fight and quarrel. You kill and covet, but you cannot have what you want."
2. The consequences of sin that comes out of the old nature include: a). A loss of peace - I Jn. 3:4-10 says, "He who does what is sinful is of the devil because the devil has been sinning from the beginning. b). A loss of love and identity with God - I Jn. 2:15,16 says, "Do not love the world or anything in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world, the lust of the flesh, the lust of the flesh and the pride of life is not of the Father, but is from the world. c). A loss of fellowship with Christians and internal purity - I Jn. 1:7 d). A loss of confidence and answers to our prayers - I Jn. 3:19-22 e). A loss of light and fellowship with God - I Jn. 1:6 f). A loss of power and eternal perspective Jesus said, "You error because you do not know the scriptures or the power of God g). Possible sickness and hyper tension - I Cor. 11:30 h). A loss of joy and motivation - Psa. 51:12 says, "Restore to me the joy of your salvation and grant me a willing spirit, to sustain me. I) Guilt and shame j). Spiritual blindness - 2 Cor. 4:4 k). Corruption - Titus 1:15 l). Condemnation - Rom. 8:1 m). Slavery to fleshly desires - Rom 5 n). A dulling of understanding - Acts 28:27 o). Distortion of one's perceptions - Eph 4:18 p) Confusion of our guidance mechanisms - Isa 53:6 q) Defiling of our speech and interpersonal relationships - Rom. 3:13,14 r). Self-deception - Jer. 17:9 s). Stifling of our discernment, growth, and creativity - Heb. 5:12-14) t). Causes one to reject good spiritual counsel - I Cor. 2:14 u). Separates one from a sweet communion with God, His grace, and His Spirit's enabling - I Cor. 16:13 v). Contentious attitudes and anger - Eph. 4:28-32
3. To overcome the sinful nature we must be led of the Spirit and not the flesh - Rom. 8:6-8 and Gal. 5:22,23 says, "Walk by the Spirit and you will not fulfill the lust of the flesh, for the flesh sets its desires against the Spirit and the flesh against the Spirit so you cannot do the things that you please. But if you are led of the Spirit you are not under the law. (Gal. 5:16-18) Exhibit the fruit of the Spirit which are love, joy, peace, patience, kindness, goodness, gentleness, faithfulness, and self-control. (Gal 5:22,23)
4. Pray and be on guard against the factors that choke out the life of the Spirit - the worries, the deceitfulness of riches, and pleasures of this life. (Mark 4:19)