Psalm 139:23-24

“Search me, O God, and know my heart; test me and know my anxious thoughts. Point out anything in me that offends you, and lead me along the path of everlasting life!”

The attributes of God are all infinitely glorious; but, like the cloud of fire, they have a different aspect towards the friends, and the enemies of God. To the ungodly, the attributes of God are dark and terrible; but to the godly, they are full of light and comfort, Exodus 15:11. His omniscience in particular is a ground both of joy and terror; in this light David speaks of it in the Psalm before us. He represents this attribute in striking colors, verse 1-12; he declares that the consideration of it was delightful to him, verse 17, 18; but the prospect it afforded him with respect to the wicked was extremely melancholy, verse 19. Returning however to his own immediate concerns, he improves this attribute to his own spiritual advantage, verse 23, 24.

From these words we may notice,

I. The danger of indulging in any secret sin.

There is no man who is perfectly free from sin, 1 Kings 8:46; but no real Christian will knowingly harbor sin. The indulging of it could not consist with his salvation. This is strongly intimated in the text. He intimates that if there were any wicked way in him, he could not be walking in the way everlasting. It is also expressly declared in other parts of Scripture.

It is said that a regenerate person cannot indulge sin, 1 John 3:9.

Allowed sin characterizes those who are of the devil, 1 John 3:8.

Allowed sin entirely prevents the acceptance of our prayers, Psalm 66:18.

Allowed sin entails on a person everlasting destruction, Matthew 5:19.

Our Lord repeatedly urges this as a reason for mortifying every sin, however pleasant or profitable it is! Matthew 5:29-30.

Nor ought this to be esteemed “a hard saying”.

The harboring of any sin is a contempt of God’s authority, James 2:10-11.

Allowed sin defeats the end of Christ’s incarnation and death, 1 John 3:8.

Allowed sin argues an entire lack of sincerity, John 1:47.

Allowed sin therefore justly brings the curse of God upon us, Jeremiah 48:10.

There is one thing indeed which renders the consideration of this extremely solemn, namely:

II. The difficulty of discerning whether we have any allowed sin in us or not.

The rule of our duty is clear enough; but it is by no means easy to determine how far our experience corresponds with it. This is evidently implied in the solicitude which David expresses for divine aid and direction. It may be confirmed also by many Scripture examples.

What ignorance of his own heart did Hazael discover? 2 Kings 8:13.

James and John little thought by what spirit they were actuated! Luke 9:55.

Nor was Peter aware of his own instability, Matthew 26:35.

Paul himself could not venture positively to determine the extent of his own innocence, 1 Corinthians 4:4.

God has declared that no one can attain a perfect knowledge of his own heart! “The human heart is the most deceitful of all things, and desperately wicked. Who really knows how bad it is? Jeremiah 17:9.”

Many reasons might be assigned for this difficulty.

The very best of our actions are blended with sin. Self-love tempts us to view them in too favorable a light; we put fine names on our bosom-sins. Hence it is hard to discern the exact quality of our actions.

To evince however that there is one way of judging aright, we shall proceed to show,

III. The means we should use for the ascertaining of it.

Self-examination is a duty inculcated in Scripture, 2 Corinthians 13:5. It is necessary for the attaining of self-knowledge. The Christian therefore can adopt the words of Asaph in Psalm 77:6. But he does not rest satisfied with his own exertions.

He is aware of . . .
“the deceitfulness of sin,”
the treachery of his own heart,
and “the evils schemes of Satan.”

Though he rejoices in the testimony of his own conscience, he dares not confide in it too much, Proverbs 28:26.

He cries to God to “search and try him”.

He remembers whose prerogative it is to search the heart, Jeremiah 17:10.

He reads the Word that God may search him with it Hebrews 4:12.

He regards conscience as God’s viceregent, Proverbs 20:27.

He looks up for the Spirit’s aid and influence, Romans 8:26.

In this way he prays, like David, frequently, and with fervor.

He commits himself to the divine guidance and direction.

He knows he shall err if God does not “lead” him; he trusts in the promises which God has given him in his Word, Psalm 25:9. Proverbs 3:6.

In this way he attains abiding peace and confidence, Philippians 4:6-7.

APPLICATION.

Let us all begin the work of self-examination.

Let us call in the divine aid with importunate supplications.

Let us inquire whether there is any sin which we habitually indulge, or some duty which we neglect?

Let us especially take notice of our “thoughts”.

Let us not think that inadvertence can excuse our sins, while we neglect the means of discovering them, Leviticus 5:17.

Let us tremble lest, through the indulgence of one sin, our religion proves vain at last, James 1:26.

Let us not walk in a way which shall serve merely for a present show, but a way that shall be of “everlasting” benefit.

Charles Simeon