“Incline not my heart to any evil thing, to practise wicked works with men that work iniquity: and let me not eat of their dainties.” Psalm 141:4 KJV
David was praying, LORD, I cry out to you, set a guard over my mouth O LORD – Do not incline my heart to any evil thing, to practice wicked works with men who work iniquity; do not let me eat of their delicacies.
It should be every believer’s prayer, “…lead us not into temptation, but deliver us from evil…” Matthew 6:13
What are wicked works?
Evil is a spirit connected with the forces of the devil. When that evil spirit embodies a person it manifests through, that manifested are wicked works or evil deeds, in the like of immorality and wickedness.
David said inline not my heart to any evil thing, to practise wicked works. All it means is it’s possible for a believer to have such evil tendencies, e.g. Saul hating David, or you not seeing eye to eye with another fellow Christian.
Romans 13:11-14 says,
“…knowing the time, that now it is high time to awake out of sleep: for now is our salvation nearer than when we believed.  The night is far spent, the day is at hand: let us therefore cast off the works of darkness, and let us put on the armour of light.  Let us walk honestly, as in the day; not in rioting and drunkenness, not in chambering and wantonness, not in strife and envying.  But put ye on the Lord Jesus Christ, and make not provision for the flesh, to fulfil the lusts thereof.”
Therefore cast off the works of darkness; adultery, stealing, covetousness, rioting, drunkenness, strife, envying, and this also; “Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law.” Romans 13:8
Do not let me eat of their delicacies
“And have no fellowship with the unfruitful works of darkness, but rather reprove them.” Ephesians 5:11
Fornication is on top of the list, and all uncleanness, covetousness, vaporising, filthiness, foolish talking, jesting.
Paul says in 1 Corinthians 5:9-11
 I wrote unto you in an epistle not to company with fornicators:  Yet not altogether with the fornicators of this world, or with the covetous, or extortioners, or with idolaters; for then must ye needs go out of the world.  But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat.
Substance abuse and drug abuse
Drugs most often associated with this include: alcohol, smoking, cannabis, barbiturates, benzodiazepines, cocaine, methaqualone, opioids and some substituted amphetamines.
“Let no man deceive you with vain words: for because of these things cometh the wrath of God upon the children of disobedience.” Ephesians 5:6
“For ye were sometimes darkness, but now are ye light in the Lord: walk as children of light:  (For the fruit of the Spirit is in all goodness and righteousness and truth;)  Proving what is acceptable unto the Lord.  And have no fellowship with the unfruitful works of darkness, but rather reprove them.” Ephesians 5:8-11