We have often struggled with trying to determine if something is sinful or not. We often try to justify or excuse our actions based upon tolerance, social trends or interpretations. Solomon gives us an excellent tool to determine if something tips the scales in the wrong direction. If we commit our actions to the Lord, it will be readily apparent when we are going against his will!
Can you imagine praying "Lord bless me while I cheat my customers" or "Lord bless me while I humiliate my enemy today"? It is obvious God's blessing and such actions are not compatible. So is the same with all sinful actions. If we submit our every act to God's will, we will no longer have to wonder if we are sinning or not: He will establish our thoughts as promised above.
Is God pleased with your actions today? Have you committed your thoughts and deeds to Him? If so, His pleasure will be a stumbling block to sin.