Each spirit, during it's inception before the foundation of the world, has anywhere from a sentence to a paragraph to maybe even a book in length worth of writing on it's reactive life form tendencies of influence; how they triggered to the strategic will of Satan. One word at a convenient time at this or that moment can be allowed to be released to you, changing your day due to the sin rules. 'God Himself tempts no one, but through evil desire sin is allowed to affect us.'
Maybe demons have evolved more with time, to an increased deceptive state as we know Satan may have been allowably pretty for awhile before being cast down from heaven. We know he was a liar from the beginning, but we know knowledge of everything occurred prior to the foundation of the world, when God conceived in visuals his work to be made manifest prior to day 1 in Genesis. Regardless, our soul is the accumulation of all the different programs of our reactive personalities. Not everyone has the gift of 'discernment of the spirits.'
There are good spirits and bad spirits that mold our perceptions and drive our actions. You can first think of spirits as understandings tied to emotions, that are understood at a deeper level than can really be explained to another. Think of the spirit of 'Anger' or 'Jealousy' or 'Joy' - they all have a deeper understanding in your mind than what you could relay in an exact pinpoint way to someone else, but your conscious knows exactly what they mean. Angels know how to condition us through Spiritual exposure off knowledge, except we get to judge them in the next life, they may not always follow the Holy Spirit’s encompassing strategic measure of all factors.
The term 'flesh' means the world in front of you in all ways physical and intellectually, that are contrary to the will of God. Evil desires of malice and ill will against others, or literal chemical and body reactions to do certain things (eat unhealthy when you know you shouldn't, have sex with someone shouldn't, etc) all play a factor to make us ALL live in the flesh in certain ways.
In Romans we know "the flesh wages war with the Spirit of God, so that you do not do the things you want to do" or something along those lines. God set these things in place before the physical world was ever even created (just like a video game programmer sets parameters within the game itself to play out for purposes of game play for the user to experience) so that we, his creation 'made in His image' learn self-control. God has to exercise self control in all things nonstop because, nothing is impossible for him (though His nature we don’t fully grasp).
With the snap of his fingers He could take our spirits from our bodies, stopping our beating hearts at any moment, the act not to do so (because of His infiniteness compared to our finiteness) are acts of mercy holding back from wrath as ‘he doesn’t deny jealousy for our affection.’ When an ant bites you, you hold back from wrath if you let it live. God exercises self control so that He can love us and share experience with Him for a huge plan that is playing out. We who are 'made in his image' also need to grasp these same concepts, in this first stage of existence.
God wants us to understand and fully grasp that we were made weak, to understand the greatness of God in comparison to ourselves. Yes I realize you have your life together and you have it figured out, I'm still pretty sure you've had difficulties that taught you things along the way - and don't be naive to think they won't still come. We humans can't not do simple things we'd rather not partake in doing. We can't not let our emotions get to us on certain things. We can't not give up certain addictions we wish we wouldn't do. We can overcome them utilizing the knowledge of God's Spirit as the good written code and force that gives us the strength to embrace and fight through the temptation. We learn His touch and how to progress from our mishaps for the sake of greater gain and inclusion with everyone in the right ways. Even when we don't realize or acknowledge that it's God working in us, we are still receiving spirits created by Him through His gifts of grace that we learn to deeper understand. There are 7 spirits of God in Revelations, and to be 'one' is to be one of will.
Just because you can control your body and someone else can't (that may willingly choose not to), doesn't mean you still aren't worse living "in the flesh," than that other person who may be overweight or addicted to something harmful. You are of the flesh if you gossip per the bible. You are of the flesh if you judge another for one infraction yet fail given the expectation or by pure hypocrisy. God is the judge, He will prove our blindness as we flawed humans time and time again can't see or grasp the circumstances that led up to why that person did what he or she did without learning the proper response. Get irritated less, be more forgiving, learn extra diligence and how to push yourself correctly given your own self risk assessment levels.
God can see those things and it upsets Him that you ignorantly base your truth on your resentment towards that other person without knowing the multitudes of factors that lead towards each others actions of which may be allowed by God given refrain and refraint verses. Hence Romans says, ‘you who judge others are only storing up wrath for yourselves on the day of Judgment.’ And another verse goes like this....With the measure you judge that other person, you will be judged the same way by a God who knows every detail behind the scene and likes mercy over letter sacrifice.
The Spirit of God is in line with His holiness. Being Holy doesn't seem worth it to many people, to embrace it for it’s good element that is. And it can't be conceptualized to every example and person, it can only be lived out to understand it. It's a purification process our souls go through, something I have worked to define in my walk. It’s a process of conditioning where you eventually can make it a full subject matter of embrace in your life if you become born again.
Things of this world that have fleshly appeal, that are contrary to holiness (where we are more naturally inclined to be available and more helpful to ourselves and others) is part of the maturation we need according to God, so we don't fail in His desire for our souls imperfect perfect state. The warnings of the bible and the ways are true, people get older and settle and can learn why they embrace these gains in their lives. Part of natural transition these things prove true, but the teachings should be embraced instead of fought against - though yes some people handle themselves and don’t have to go there.
The more you work to be of the 'Spirit of God,' the more you get gifts of grace that add meaning to your life that align with the assurance of eternity where trusting God becomes the better choice than worry or lack of the concern needed to believe in fate and faith.
An example of a gift of grace, shot down from the spiritual realm to our conscious, is peace. Grace comes in many forms, we need to learn to become perceptive of it and strive for it and be thankful and mindful when God gives us grace in our day. That's called being spiritual. To finally learn to grasp what it means to experience joy, instead of self-seeking shallow happiness which is more about yourself than sharing in joy with people you care about is the difference in discernment you need to be accustom with. We all can’t hear every word perfect in conversation, but it matters to share joy and go there with others.
You need to understand how to give love. How to receive love so that others can share in the greatest gift God gave to us in existence, which is love. Don't rob someone the joy of doing something nice for you. Don’t rob someone who needed a little love either by not being proactive to the degree necessary.
Whether you act 'of the flesh' in regards to addiction against the rules and standards of adherence, or following desires of the spiritual flesh the 'spirit of disobedience in the air' (spirit/teachings of demons who lightly condition your conscious to be at war with the Spirit of God's perfection.) The will of Satan is to half eye see and then to judge others for the sake of self vindication, to prefer malice, to malign, not forgiving others to the same degree of recent memory, utilizing gossip as strategy, unhealthy resentment towards others made rightfully different than you – these sins spirit flesh sins create difficult pains (and sexual immorality is a deception practice too besides just flesh flesh) so stay true to the Golden Rule to the best of your ability because of the fear of the Lord's system.