“My son, keep my words and store up my commands within you. Keep my commands and you will live; guard my teachings as the apple of your eye. Bind them on your fingers; write them on the tablet of your heart.” (Prov. 7:1-3 NIV)

There is a little book written by Dodie Osteen, “Healed of Cancer,” which tells her amazing story of how God healed her of pancreatic cancer. She had reached the stage where her skin had turned yellow, and the doctors had given up and told her there was nothing more they could do except send her home to die. But instead of giving up, she decided to apply God’s Word with faith. She began by looking up all the healing verses in the Bible. She wrote them down by hand in a notebook, poured over them daily, and claimed them with faith for herself. She memorized, personalized, and spoke out loud key verses like, “I shall not die, but live, and declare the works of the Lord.” (Psalm 118:17 KJV), and “He Himself bore my sins in His body on the cross, so that I might die to sins and live for righteousness; by His wounds I have been healed.” (1 Peter 2:24). She also placed on her walls lots of pictures of herself as healthy and well; these constantly reminded her of good health. And it worked. She did not die, but improved a bit every day until she became totally well and healthy again. Dodie’s testimony is a great example of the promise at the top: “Keep my commands and you will live; guard my teachings as your own.”

Therefore 

“If you abide in me, and my words abide in you, ask whatever you wish, and it will be done for you.” (John 15:7)

“What you have learned and received and heard and seen in me—practice these things, and the God of peace will be with you.” (Phil. 4:9)

“The thief comes only to steal and kill and destroy. I came that they may have life and have it abundantly.” (John 10:10)

“So faith comes from hearing, and hearing through the word of Christ.” (Rom. 19:17)