Fasting is voluntarily setting aside food (or other things) for a time to focus more fully on prayer and seeking God, not a way to manipulate God or earn favor.
Throughout Scripture, fasting accompanies serious prayer — seeking guidance, repenting, or drawing near to God in times of crisis or decision. Jesus assumed His followers would fast and taught that it should be done sincerely, without seeking public attention or praise for the sacrifice. Fasting is not a technique to force God's hand or a means of earning spiritual credit; rather, it is a physical way of expressing humility and dependence, clearing space so attention can focus more fully on prayer and listening to God.
These themes are best read through the whole testimony of Scripture, emphasizing God's self-revelation in Christ, the active ministry of the Holy Spirit, and the restoration of the whole person. Bible study should lead to a changed life, compassionate service, and a clearer picture of God's loving character.