This psalm asks an important question, “Who may enter into God’s presence and have fellowship with Him?” God’s standard is perfection (Mt 5:48), and this psalm speaks of a level of righteousness impossible apart from God’s grace. This psalm is to show a redeemed person how to maintain fellowship with righteous God.
All believers must live their life in obedience to God’s standard if they are to maintain their communion with God (Jn 15:10). Consistent obedience is required of God’s people to be able to worship Him appropriately (1 Sam 15:22).
David tells us in this psalm that the true worshipper will live a life of integrity, love, and selflessness. A person of integrity is constant and consistent in their belief and behavior (15:2). They live out God’s truth by living righteously (15:2). The true worshipper will also demonstrate his love for his neighbor by how he acts. They will not gossip about another person and cause them pain. They will not personally attack others and ridicule them, but rather bring a blessing (15:3). The righteous person will seek to fellowship and honor those that fear the Lord and not the wicked (15:4). They will seek others above themselves even if it costs them something personally. They are not worldly and greedy, and they seek to help those in need without expecting to get something in return. (15:4).
This is a high standard that all believers of all time are called obey. It is what we strive for in Christ as we walk with Him and are conformed to His image (Rom 8:28-30). The sanctified life, an obedient life, is what brings security and communion with the LORD (15:5).