Here is Leithart again on the resurrected and living Christ as the life of those whom he indwells by his Spirit and whose lives are hidden in him.
One caveat: when Leithart says, "We died with Christ, and Christ lives in us by the Spirit so that our lives conform to His life, repeatedly dying and living again", he doesn't mean that Christ repeatedly dies and lives again, as though he is proposing some perpetual or repeated sacrifice of Christ. Christ died once to accomplish salvation:
For Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit (1 Pet. 3:18)
For Christ has entered, not into holy places made with hands, which are copies of the true things, but into heaven itself, now to appear in the presence of God on our behalf. Nor was it to offer himself repeatedly, as the high priest enters the holy places every year with blood not his own, for then he would have had to suffer repeatedly since the foundation of the world. But as it is, he has appeared once for all at the end of the ages to put away sin by the sacrifice of himself. And just as it is appointed for man to die once, and after that comes judgment, so Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him. (Heb. 9:24-28)Rather, Leithart is talking about our lives and the pattern of life we are called to live in imitation of Christ. We are called to a pattern of dying to self, sinful desires, temptations of the flesh, remnants of the old person, the world, and living to Christ and living for others. That is the repeated pattern of dying and living again.