We are truly heartbroken to hear about your sister's condition and the pain she is experiencing. We will stand with you in prayer and belief that God can intervene in this situation. First, let us address the spiritual aspects. First, we are not promised an easy life, but we are promised that God will be there for us in our trials. Even in our suffering, God's grace is sufficient, and His strength is made perfect in weakness. But, we must call upon the name of Jesus Christ, not only for salvation, but for help in this life. We must believe in our hearts and confess with our mouths in Jesus Christ.
2 Chronicles 7:14 WEB if my people, who are called by my name, will humble themselves, pray, seek my face, and turn from their wicked ways; then I will hear from heaven, will forgive their sin, and will heal their land
James 5:13-16 WEB Is any among you suffering? Let him pray. Is any cheerful? Let him sing praises. Is any among you sick? Let him call for the elders of the assembly, and let them pray over him, anointing him with oil in the name of the Lord, and the prayer of faith will heal him who is sick, and the Lord will raise him up. If he has committed sins, he will be forgiven. Confess your offenses to one another, and pray for one another, that you may be healed. The insistent prayer of a righteous person is powerfully effective.
But, let's not forget the power of the name of Jesus Christ:
John 14:13-14 WEB Whatever you will ask in my name, I will do it, that the Father may be glorified in the Son. If you will ask anything in my name, I will do it.
Acts 4:12 WEB There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved
Know that God's Word is true, and He will direct us if we will listen and obey. If something is hindering us, we must fix it. Therefore, we will pray for discernment and guidance for the root cause of this terrible situation. Then, we can better pray and believe for healing and comfort for your sister. We will ask that God will give her the strength to endure and that His peace will fill her heart. We will also pray for the wisdom and guidance for the medical professionals attending to her, that they would be led to the best course of action for her healing. Please pray with us:
Heavenly Father, we come before You in the mighty name of Jesus Christ, lifting up our sister who is battling stage 4 cancer and experiencing terrible pain. We ask, Lord, that You intervene and alleviate her suffering. Give her strength, Lord, to endure this trial and fill her heart with Your peace. Guide the medical professionals, Lord, and give them wisdom to administer the best care for her healing. We also ask for Your forgiveness and guidance if something needs to be addressed in her life. We know that You are able to heal and deliver. We pray this believing in the name of Jesus Christ. Amen.