Psalms 64:6
They search out iniquities; they accomplish a diligent search: both the inward thought of every one of them, and the heart, is deep. They search out iniquities; they accomplish a diligent search: both the inward thought of every one of them, and the heart, is deep.
The verse portrays evildoers as deliberately hunting out wrongdoing and carrying through an exhaustive, diligent search, probing deeply into one another's hidden inward thought and heart. In that same setting the workers of iniquity embolden and encourage one another in an evil plan, confer and commune together to lay hidden snares in secret, and attack the blameless and perfect with harsh, bitter, wounding speech like arrows shot at them. This depiction of their plotting will come true literally. That literal fulfillment will take place in a time of shaking when everything that can be shaken is shaken and removed, so that only the things that cannot be shaken remain and endure. God will keep a pure and holy people who will stand and endure that test in the past, in the present, and in the future.
In response every believer should now thoroughly examine his own heart as if by the light of a lighted candle. That self-examination means learning what to do to inherit eternal life by loving God with all heart and soul and strength and mind and by loving one's neighbor as oneself, and by doing this and living out that love.