From his excellent book Luther for Armchair Theologians, my old teacher Dr. Steven Paulson writes on the absolute omnipresence of Christ:
"Luther is even willing to pause for a minute and talk about Christ's body being wherever Christ is- and that means everywhere present! Of course, this makes human reason and its buff, free will feel crowded out of the world."
In other words, human reason that lusts for self-justification through imaginary free will, is "crowded out" of the world when it recognizes that Christ is all-present "for you." If the gracious God found in the flesh of Jesus reigns and is present everywhere, the human person loses all their power to establish themselves before God by their good works. There is no distance from this incarnate God within which they can use their free will in order to move towards him. They can only accept in faith that Christ is all-present and gracious pro nobis.