"this is the kind of fasting I want: Free those who are wrongly imprisoned; lighten the burden of those who work for you. Let the oppressed go free, and remove the chains that bind people." Isaiah 58:6
This is a promise of freedom, but it is conditional. It requires faith, prayer, and fasting. God provided the ritual of denying yourself to focus on prayer so that people could pursue Him in times of need, difficulty, or growth. It was never meant to become a ritual to show how good you are as a "Christian".
The point of fasting is to get closer to God, but it also comes with many different types of perks. The problem is that some people remove God from the process in hopes to just have the perks. You focus on your relationship with God and who you are with Him. Your prayers will be answered, but there are other benefits too. You may look younger, become healthier, get more energy, and find wisdom that leads to freedom.
The promise is conditional because you have to do your part to discover the freedom that comes with salvation. As your eyes open to the truth you have to make changes in your life to maintain your freedom. It does not mean you will be free from every type of oppression or discomfort. It is a spiritual and sometimes healing kind of freedom. It is freedom from the constraints of the world that say you have to be a certain way or live a certain way to be worthy, happy, or a person that matters.
Fasting looses the hold that evil has in your life. It leads to a closer relationship with God. You become more self-disciplined, so you are able to focus on your relationship with God as a decision. It leads to patience and enables you to endure in life because you know what you have no one can take from you. It build stronger character because you discover the value of it. The burdens of wickedness are removed as you desire to live your life with God. Once you obtain this freedom, then you should want to help other people discover it.
The promise of freedom comes with a command and laying out His expectations, so that when you worship Him you discover freedom. Freedom always cost something. Jesus paid that cost, so you can be a Christian and inherit a level of freedom. The freedom become powerful when you learn to fast, pray, and dig into His Word. The freedom helps you uphold justice, remove burdens yourself enabling you to identify them, and withstand being broken by oppression. God's light lives in His people, so you can find the way through, find healing, and protect righteousness. Freedom exist in faith.
Nehemiah 5:10-12, Isaiah 58:5-8, Jeremiah 22:3, 34:9, Micah 6:8, Zechariah 7:9-10, Luke 4:18, James 2:15-16, & 1 John 3:17-18