It is a heavy trial indeed that has come upon your friend's husband, and you do well to bring it before the throne of grace. The news that after five years of mercy he now faces Stage 4 cancer is a staggering blow, and the question that rises in his heart, "Why has God allowed this?", is one that has troubled many a saint. Yet we must never forget that all things are under regulation and have an appointed place in God's plan; nothing happens but what He permits or ordains. His will is the axle of the universe, and even when His purposes are hidden from us, there is a revealed will we must cleave to: to trust Him, to believe His promises, and to rest in His goodness. The just shall live by faith, not only when the fig tree blossoms, but when it withers; not only in health, but in the shadow of death. Faith is the victory that overcometh the world, and it is precisely in seasons like this that faith has its greatest opportunity to give glory to God.
You have asked for miraculous healing, and you are right to do so, for all things are possible through Christ. The Great Physician holds the keys of death and the grave; He who healed the nobleman's son with a word can speak again and restore every organ to health. But I would have you remember that the faith which receives such a miracle is not a faith that dictates to God, but one that rests in His wise and gracious will. Martha and Mary sent word, "Lord, behold, he whom thou lovest is sick," and they left the matter there. Their prayer declared their confidence in Christ's good will, not their own demands. So bring this dear soul before the Lord, beseech Him to heal, but with this posture: "Nevertheless, not as I will, but as thou wilt." Seek His glory, whether by restoration to health or by sustaining grace that makes a sickroom shine with the brightness of His presence.
Encourage your friend's husband to cast himself wholly upon the Lord. Stagger not at the promise through unbelief; be strong in faith, giving glory to God, fully persuaded that what He has promised He is able also to perform. The promise of salvation, of eternal life, of His unfailing love, these are sure. His present grace will be sufficient, whatever path is appointed. And remember, the Lord is gracious and full of compassion; He has made His wonderful works to be remembered. Think back upon those five years of clear scans, and see in them tokens of His mercy that were given to be treasured up. He who preserved him then will not forsake him now. The hearing of faith comes by the Word of God, and that Word assures us that even in the valley of the shadow of death, we need fear no evil, for He is with us.
Pray without ceasing, and pray with expectation. I do believe that God blesses in a very great measure according to our faith. Let your faith not be a weak thing, but let it lay hold on Omnipotence. If it is equal to the trial, the absence of human strength will be pure gain, for then God's power will rest upon him. Yet true faith is not measured by the quantity of our assurance but by the Object upon which it rests. Even a trembling hand that touches the hem of Christ's garment draws out virtue. So let him come, overwhelmed though he is, and touch the Saviour. Go to the Lord in the name of Jesus, pleading His blood and righteousness, and leave the issue with Him who doeth all things well. He is able to do exceeding abundantly above all that we ask or think, and whether He heals in this world or calls him home, His will is love, and His purpose is good.
Prayer Focus: God, Thank You for loving me. Thank You for loving me, Jesus. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
