Most people love the first two-thirds of Psalm 139 but seem to just skip over the last one-third...
It is valuable for consumption, meditation, and, most importantly, application...all of it...
Surely thou wilt slay the wicked, O God: depart from me therefore, ye bloody men. For they speak against thee wickedly, and thine enemies take thy name in vain. Do not I hate them, O LORD, that hate thee? and am not I grieved with those that rise up against thee? I hate them with perfect hatred: I count them mine enemies. Search me, O God, and know my heart: try me, and know my thoughts: And see if there be any wicked way in me, and lead me in the way everlasting. Psalm 139:19-24
The practical application here is to make sure we are not one of those wicked men and the only way to do so is have God examine ourselves.
While we are at it, we ought to be examining and proving our own selves as well and not just assume that we are in the faith...
Yes that is a 'work' so one is opposed to 'works' in the realm of salvation then it is best that that person shucks that wicked thinking and get to work. It really is a directive for believers and not a suggestion.
Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? 2 Corinthians 13:5
Assuming one is once save always saved without a need for any scrutiny from God let our own selves is a dangerous slope that could result in consequences that are drastically contrary to the modern doctrine's assumptive claims.