Healing is not guaranteed by the atonement, it is provided by the atonement.

A man's doctrine: The only thing standing between a Christian and perfect health is sin or a lack of faith, because healing is the privilege of all believers. While ultimate physical healing is in the atonement (a healing we will enjoy in our resurrection bodies), healing of our bodies while in the mortal state (prior to our death and resurrection) is not guaranteed in the atonement. Christ's atonement provided us with a means to obtain a resurrection to eternal life with no more sickness, death, or suffering, so in that sense, yes, healing was provided for in the atonement. What I will be discussing is the popular teaching of healing in the atonement which teaches that the realization of all the benefits of the atonement belong to us in the here and now. I believe that God can and does heal people today. I believe in the gift of healing. God may heal people in answer to prayer, and he may empower some with the gift of healing. What I am arguing against is the idea that temporal physical healing is guaranteed. Too many people mistakenly assume that if a person doesn't believe in healing in the atonement that the person doesn't believe in healing at all, and that's just not the case. Many who fail to receive healing claim to have "exercised faith" but the Bible makes it, very, clear that the prayer of the faithful will be heard and granted. Is the Bible in error, or do we just have a faulty understanding of faith? What is the true nature and source of faith? From a Christian perspective, we believe that God's Word is true and that He can be trusted to perform all that He has promised. Our faith is in God, not in faith. Faith itself has no intrinsic power, rather the power resides with the one in whom our faith is placed. Those who have proclaimed healing in the atonement the loudest have sometimes burdened the sick ones with more guilt about being sick. In their zeal to defend what they perceive to be an important Bible truth, they have offered no comfort to those who, for whatever reason, are not healed. This of course, is not helpful. But neither is maintaining an incorrect view of the scriptures in order to justify our experience. So often God’s sovereignty is offered as the answer when we don’t experience the things promised by the word. “God is sovereign over His sovereignty” someone said. (Whatever that means!) Charles Spurgeon said “Before he pledged his word he was free to do as it pleased him; but after he has made a promise, his truth and honour bind him to do as he has said. To him, indeed, this is no limiting of his liberty; for the promise is always the declaration of his sovereign will and good pleasure, and it is ever his delight to act according to his word; yet is it marvelous condescension for the fee spirit of the Lord to form for itself covenant bonds.