The summit of a mountain is its highest point. It’s peak; the pinnacle. Most people don’t live on the summit because it’s so hard to get to; only the most adventurous and courageous can climb that high.
Many people consider Romans chapter 8 to be the summit of New Testament theology. It’s been called the greatest chapter in the bible. And yet, Romans 8 isn’t intended to be a lofty peak to which only a few attain. It’s actually the summation of the Christian life and describes what Jesus has obtained for those who live by faith.