Dr. John MacArthur writes: “In eternity, all sickness will be removed, so ultimately, healing is included in the benefits of the atonement” (The MacArthur Bible Commentary, p. 825). We have no right to expect that all our illnesses will be healed in this present age, only in the eternal state will Christ’s work be fully applied and all disease gone. Still, we should pray for the sick knowing that our God may bring healing if we ask in faith and trust in His good purposes.
For further study:
The Bible in a year: