We are truly sorry to hear about your father's diagnosis. We stand in the gap for you. The Bible tells us in 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.
First, we acknowledge that "there is no other name under heaven that is given among men, by which we must be saved" Acts 4:12 WEB. We pray that your father has accepted Jesus Christ as his Lord and Savior. Then our prayers can be most effective. We invite you to believe in Jesus Christ for salvation for yourself and your family. This is the most urgent matter and we want to make sure that your family has this assurance. Jesus said "I am the way, the truth, and the life. No one comes to the Father except through me" John 14:6 WEB.
We are reminded of the healing power of Jesus, as seen in Matthew 8:1-3, 14-17 WEB:
When he came down from the mountain, great multitudes followed him. Behold, a leper came to him and worshiped him, saying, Lord, if you want to, you can make me clean. Jesus stretched out his hand, and touched him, saying, I want to. Be Be healed. Immediately his leprosy was cleansed.
Jesus came to Peter's house, and saw his wife's mother lying sick with a fever. He touched her hand, and the fever left her. She got up and served him. When evening had come, they brought to him many possessed with demons. He cast out the spirits with a word, and healed all who were sick; that it might be fulfilled which was spoken through Isaiah the prophet, saying: He took our infirmities, and bore our diseases.
So let's stand in the gap for your father and pray together.
Almighty God, we come before you in the name of Jesus Christ, believing in His power to heal and save. We pray for our brother who is battling glioblastoma. Lord, we ask for Your healing touch upon him. Comfort him with Your presence, and give him the strength to endure this trial. We pray for his complete healing, that he may continue to be a blessing to his family and see his daughter walk down the aisle and meet his future grandchildren.
We also pray for his family, that You would fill them with Your peace and strength during this time. Help them to trust in Your goodness and faithfulness, no matter what the outcome may be.
We pray specifically for our brother to be a part of the family of believing in Jesus Christ. We pray for his salvation and those of his family if not already believers.
Please bring glory to Yourself through this journey with cancer. In Jesus' name, we pray. Amen.
Be strong and courageous, for the Lord your God is with you wherever you go Joshua 1:9.
We encourage you to seek the Lord in all things, trusting that He works all things together for good for those who love Him and are called according to His purpose Romans 8:28. Continue to pray and seek His face, and trust in His unfailing love and faithfulness.
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
