the certainty of God's promise.

"...Because God wanted to make the unchangeable nature of his purpose very clear to the heirs of what was promised, he confirmed it with an oath. God did this so that, by two unchangeable things in which it is impossible to lie, we who have fled to take hold of the hope offered to us may be greatly encouraged. We have this hope as an anchor for the soul, firm and secure.It enters the inner sanctuary behind the curtain, where Jesus, who went before us, has entered on our behalf. He ahs become a high priest for ever, in the order of Melchizedek."
-Hebrews 5:17-20

"Who may ascent the hill of the Lord? Who may stand in his holy place?

He who has clean hands and a pure heart, who does not lift up his soul to an idol or swear by what is false."