Updated: Sep 14, 2020
Psalm 15 speaks about those who are truthful in their hearts. A person who honors God, fears God and is always devoted to God. We all wish to be this way but the reality is different.
The question who will dwell on the Holy Mountain is repeated earlier in the Psalms. It is not us but Christ that dwells there in the temple. Christ then came as the temple in a human body to be "tabernacled" ( John 1:14) among us. Only Christ can restore man to God. Our devotion to him and the Holy Scriptures along with prayer is the way, the truth and the life.
A psalm of David.
1 Lord, who may dwell in your sacred tent? Who may live on your holy mountain?
2 The one whose walk is blameless, who does what is righteous, who speaks the truth from their heart; 3 whose tongue utters no slander, who does no wrong to a neighbor, and casts no slur on others; 4 who despises a vile person but honors those who fear the Lord; who keeps an oath even when it hurts, and does not change their mind; 5 who lends money to the poor without interest; who does not accept a bribe against the innocent.
Whoever does these things will never be shaken.