One must always guard one’s own heart because once your heart it influenced you will surely start acting out as per your own intentions. It is silly to blame only the devil for all the bad things that happen in the world. People also sin because they choose to do from their own heart.
A serial killer, allows thoughts of murder in his heart on a great level, which then lead him to commit murder. He had a choice to not allow murderous thoughts but he let it be otherwise. No wonder his sin is upon him.
No adulterer can say that they had absolutely no lustful thoughts before getting into the vile sin of adultery. As much as they were aware of their marriage vows so also in that measure were they aware that thoughts of lust and immorality are entering their heart. They had their choice to say no but simply bypassed that. That is why they are in sin.
Christian martyrs (God bless them) chose to let only thoughts of faithfulness to Jesus be in them. That is why even in the face of imminent death they chose to keep their faith in Jesus and die for him rather than reject him. That is why they are worthy disciples of Jesus.
Do have good and holy thoughts that lead you to all actions that glorify God. The more you allow thoughts that are worthy, the better will your walk of faith be in Jesus. Avoid giving your heart to silly and vulgar jokes, immoral forms of entertainment, worthless books and novels, hate promoting songs, this list could go on and on but I do hope that you got my point.
Here are a few scriptures that you could reflect on:
Proverbs 4:23 Above all else, guard your heart, for everything you do flows from it.
Matthew 12:34 You brood of vipers, how can you who are evil say anything good? For the mouth speaks what the heart is full of.
Matthew 15:18-19 But the things that come out of a person’s mouth come from the heart, and these defile them. For out of the heart come evil thoughts–murder, adultery, sexual immorality, theft, false testimony, slander.
Mark 7:21 For it is from within, out of a person’s heart, that evil thoughts come–sexual immorality, theft, murder,
Luke 6:45 A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of.
Deuteronomy 4:9 Only be careful, and watch yourselves closely so that you do not forget the things your eyes have seen or let them fade from your heart as long as you live. Teach them to your children and to their children after them.
2 Kings 10:31 Yet Jehu was not careful to keep the law of the LORD, the God of Israel, with all his heart. He did not turn away from the sins of Jeroboam, which he had caused Israel to commit.
Proverbs 23:19 Listen, my son, and be wise, and set your heart on the right path:
Deuteronomy 4:9 Only take heed to yourself, and keep your soul diligently, lest you forget the things which your eyes have seen, and lest they depart from your heart all the days of your life: but teach them to your sons, and your sons’ sons;
Mark 14:38 Watch ye, and pray that you enter not into temptation. The spirit indeed is willing, but the flesh is weak.
1 Peter 5:8 Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: