Make every effort to live in peace with everyone and to be holy; without holiness no one will see the Lord. See to it that no one falls short of the grace of God and that no bitter root grows up to cause trouble and defile many. See that no one is sexually immoral, or is godless like Esau, who for a single meal sold his inheritance rights as the oldest son. Afterward, as you know, when he wanted to inherit this blessing, he was rejected. Even though he sought the blessing with tears, he could not change what he had done.
You have not come to a mountain that can be touched and that is burning with fire; to darkness, gloom and storm; to a trumpet blast or to such a voice speaking words that those who heard it begged that no further word be spoken to them, because they could not bear what was commanded: “If even an animal touches the mountain, it must be stoned to death.” The sight was so terrifying that Moses said, “I am trembling with fear.”
But you have come to Mount Zion, to the city of the living God, the heavenly Jerusalem. You have come to thousands upon thousands of angels in joyful assembly, to the church of the firstborn, whose names are written in heaven. You have come to God, the Judge of all, to the spirits of the righteous made perfect, to Jesus the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel.
See to it that you do not refuse him who speaks. If they did not escape when they refused him who warned them on earth, how much less will we, if we turn away from him who warns us from heaven? At that time his voice shook the earth, but now he has promised, “Once more I will shake not only the earth but also the heavens.” The words “once more” indicate the removing of what can be shaken—that is, created things—so that what cannot be shaken may remain.
Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe, for our “God is a consuming fire.” - Hebrews 12:14-29
The holiness of God is always in front of us. There were people who look backwards for "the experience of God" and see that as the turning point in their lives. Indeed, many of the psalms and prophets recount how impressive God's actions in the lives of Israel were. But they also record how Israel is not acting like Israel. The impressive miracles of the past are just that: in the past.
But here, the author of Hebrews reminds us that what defines holiness is not reliance on what happened but on will happen. Holiness is a today and tomorrow choice, not a fond recollection of yesterday. And it is not an attribute of God that leads to diminishing returns, like a candy bar whose second bite is less tasty that the first. God increases with familiarity, unlike nearly all other stimuli that we experience, because he is a living God, a consuming fire.