Psalms 73:18

Surely thou didst set them in slippery places: thou castedst them down into destruction.

The verse answers the perplexity felt when transgressors and sinners are allowed blessings and prosperity while those who love God are compassed with difficulties, showing that God's ways are not unequal. God Himself sets the wicked in slippery places, so that even when they appear secure their standing is insecure, precarious, and unstable, like sliding ground. Their pride and unbelief are what leave them on that slippery ground. God casts them down into destruction, bringing them to sudden ruin and desolation in a moment, utterly consumed with terrors, so that apparent prosperity offers no protection from His retributive justice and wrath. This end is not understood until one goes into the sanctuary of God.

Seeing that end removes envy of the foolish and the feeling of being abandoned, exposes doubting God as foolish and ignorant, and leads to remaining continually with God as He holds by the right hand, finding it good to draw near to Him, put trust in Him, and declare His works. Slippery places also picture positions of service assigned by God's providence where footing is insecure and feet can easily slide, and where a single wrong move can injure one's usefulness and thereby imperil souls. Safety in such a place requires giving oneself to prayer to be kept by God's power, maintaining integrity, and working in a straightforward manner as Christ's ambassador, walking before Him in consistency and uprightness that represents the loveliness of His character.

The verse warns against relying on people whose footing is unstable and whose hearts are not at rest. Applied to Jones, it warns that his unsanctified thoughts and affections and his continued course placed him in danger and invited temptation, and that without seeking God's help and guarding his soul he risked a downfall like Waggoner's. It warns those whose indulgence in sexual passion weakens their bodies and minds and harms their children that they stand in slippery places in peril of a sudden fall and need their eyes opened to the danger.