The answer to the question: to whom does the Lord give his protection and security? is given in Psalm 15:2–5. It consists of eleven characteristics of believers: three stated positively, three negatively, three more positively, and finally two more negatively. These elements are a brief summary of the Law. The first three positively stated characteristics are found in Psalm 15:2, that is, the righteous is he who walks blamelessly, does what is right, and speaks the truth.
Instead of blameless, we could also say: with undivided heart.
Yahweh demands integrity from his people. But how can we be blameless, when all our works are imperfect and polluted by sin? According to Scripture, it really is possible to walk blamelessly. Noah (Genesis 6:9), Job (Job 1:1), David (2 Samuel 22:23–25), Zechariah and Elizabeth (Luke 1:6) are all described as blameless. These people were not blameless because they were perfect; their sins and shortcomings are recorded in Scripture. They were blameless because they walked with an undivided heart. They walked righteously in the light of the covenant.
Righteousness means being loyal to God’s covenant, being obedient to his laws, and believing in his promises. A righteous person is a person of truth.
2 He who walks blamelessly and does what is right and speaks truth in his heart;