Daily Reading: (Galatians 5:16-21):
“So I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want. But if you are led by the Spirit, you are not under the law.The acts of the flesh are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.”
“Freedom in Christ” is the main point of Galatians chapter five. When we reach verse sixteen we have are introduced into the sub-header: “life by the Spirit”. So we have freedom in Christ expressed through life by the spirit.
Which what Paul is saying is “do not use your freedom to indulge the flesh; rather, serve one another humbly in love.”
“So I say, walk by the Spirit, and you will not gratify the desires of the flesh.” The question really becomes, “how are we to walk by the Spirit and what does it mean to walk after the flesh?” Most people actually read this verse the other way around. “Do your best not to fulfill the desires or lust of your flesh, and then you’ll walk in the Spirit.” That is not what Scripture says or teaches us here. The Scripture teaches this not in the negative but in the positive. “walk by the Spirit, and you will not fulfill the lust of the flesh.” As you walk by the Spirit you won’t have to worry about the lust of the flesh.” Our focus has to be on walking in the Spirit. If you are focused on trying not to fulfill the desires of the flesh that is living your life under the Law. And if you live this way you’ll end up walking after the flesh. Walking after the flesh is an attempt to meet any of your needs apart from God.Romans 8:13 tells us this is a disastrous way to live.
So, how do we walk by the spirit or what is walking by the spirit? John Piper says, “It is “being led by the Spirit” and it is “bearing the fruit of the Spirit. You allow the Spirit to control you by keeping your heart happy in God. Or to put it another way, you walk by the Spirit when your heart is resting in the promises of God.” 
George Müller learned the secret of walking by the Spirit: meditate on the precious truths of the word of God until your heart is happy in God, resting in his promises.
“Walk by the Spirit, and you will not gratify the desires of the flesh.” You will have victory over temptation and know the guidance of the Lord if you keep your heart happy in God by resting in his promises.
We get a better understanding in the Greek for the word “walk” (peripateō) which means to be led around. This brings us to Psalm 23:3, “He guides me along the right paths for His name’s sake.” This is what it means to walk by the Spirit.
“For as many as are led by the Spirit of God, these are the sons of God” (Romans 8:14). “My sheep listen to my voice; I know them, and they follow me” (John 10:27). Habits of the flesh will all fall off as we walk in the Spirit (Galatians 5:16).
The Spirit of the Lord will move you to a place of rest and refreshment where you cast your cares on Him. Troubles and stresses will come, but walk by the Spirit to the place of lying down in green pastures. Enjoy the feast God prepares for you in the presence of those plaguing enemies that have risen up against you.
“Let us therefore give diligence to enter into that rest, lest anyone fall after the same example of disobedience.” (Hebrews 4:11 WEB)
Rest is not inactivity—it is Spirit-directed activity. The opposite of being in God’s rest is being in unbelief.
“For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh.” They are in conflict with each other, so that you are not to do whatever you want. I wanted to point out that the fight is not between you and the flesh, the fight is between the flesh and the Spirit.
Here is the good news: you are not under the Law any longer because we have freedom in Christ, freedom to live by the Spirit that He has placed inside us. Live as the new creation we have become. Live out of our new God-given nature that reflects His glory. Galatians 5:16 promises victory over the desires of the flesh, not that there won’t be a war, but that the winner of that war will be the Spirit.
 John Piper. The War Within: Flesh Versus Spirit. June 19, 1983. https://www.desiringgod.org/messages/the-war-within-flesh-versus-spirit
 George Müller. Autobiography 152–154.