1) Are you saying that people can only fast spiritually?
Let me be clear. One can exclaim to the world you are fasting. And everyone would see it. But according the Bible:
Isa 58:3 Wherefore have we fasted,
say they, and thou seest not?
wherefore have we afflicted our soul, and thou takest no knowledge? Behold, in the day of your fast ye find pleasure, and exact all your labours.
Isa 58:4 Behold, ye fast for strife and debate, and to smite with the fist of wickedness: ye shall not fast as
ye do this day, to make your voice to be heard on high.
Isa 58:5 Is it such a fast that I have chosen? a day for a man to afflict his soul?
is it to bow down his head as a bulrush, and to spread sackcloth and ashes
under him? wilt thou call this a fast, and an acceptable day to the LORD?
Isa 58:6 Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?
Isa 58:7
Is it not to deal thy bread to the hungry, and that thou bring the poor that are cast out to thy house? when thou seest the naked, that thou cover him; and that thou hide not thyself from thine own flesh?
Isa 58:8 Then shall thy light break forth as the morning, and thine health shall spring forth speedily: and thy righteousness shall go before thee; the glory of the LORD shall be thy rereward.
As you see... verse 6 explains the reason to fasting very clearly. It also explain in the previous verses where people fasted and God did not adhere to them. For they try to use fast as a manipulation. To turn God's arm to receive things.
God will never allow this.
The fast is to grow spiritually and to destroy evil in one's life. To grow in faith.
Mat 17:20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.
Mat 17:21 Howbeit this kind goeth not out but by prayer and
fasting.
Here again it was needed to fast to have the faith to cast out a demon.
Therefore it is important that one fast out of obedience and for the things of the Spirit. For that is the reason why one stays without food. To cleanse one self from the fleshly desires so the spriritual can grow.
2) Are you saying that someone who fasts spiritually cannot benefit physically or mentally or emotionally?
All benefits which you should be focussing on should be that of establishing a better connection and relationship between you and God. Will it affect you physically, mentally and emotionally. Yes to all of them. But your focus should not be to gain there. But to gain with God.
3) Are you saying that the longer you go without food the easier it is to go without food? Scientifically this is true for us humans, after 5 days your appetite diminishes, and scientifically it returns at around the 40th day. After 40 days I'm sure that hunger returns with a fury.*I wonder is that to show us Jesus humanity?Satans timing, a hit Him when He would be most inflicted by the flesh?* Just a thought or two on the topic.
It is interesting that scientist happen to prove the grace of God. But from the first day already you will start to have very little appetite and on the second none. For your focus is on the grace and obedience of God. And if done in obedience then the grace of God would be apparant. However Jesus could have gone 60 days if it needed be, however for the sake of the value of 40 and the meaning behind it, he simply did 40 days.
4) David fasted from desserts, can you not do the same for the Lord?
The act of one's fast is dependant on the instruction of the Lord God. That is why I said it is an act of obedience. One cannot obey if one did not first listen to an instruction. But fasting doesn't come from your own desires, for the purpose behind fasting is to negate desires. So why in effect would you try to fulfill something you are trying to negate. For the purpose of fasting is to place all your desires in submission to that of God. Your entire nature and being in submission to that of the will of God.
Just some questions I have. I've never met an expert on fasting and wanted to know where you were coming from. I firmly believe that the only way to the Father is through the Son, and I believe that journey is as unique per each believer as each believer is unique.
No one is truly an expert except He who teaches all who is the Holy Spirit. But those still young and stubborn often forget that they have to heed His voice first so He can remind and teach them in the ways that Christ has layed down for us. As for being unique. We are three siblings in our house. Each one our parents treats differently. But we are all subjugated to the same rules in our house. God has rules too. He has ways of doing things correctly and incorrectly and even though He is bountifully mercifull towards us if we do things wrong, because we are weak and afraid. He still grace us with the gifts of His heart. It is still good to pray and fast correctly. For there are guidelines for prayer also, and a lot of people do not do them. But those were the guidelines given by Christ when His disciples asked Him to teach them how to pray. That doesn't mean God isn't graceful. But it does mean He has set methods.
As to your last and least important question. Where am I coming from. I come where I am send and go where I am send. I live by His grace and by His voice. I try to aid others in their believe and fulfill the desires of God for me. I plead for mercy daily and for forgiveness and pardon to the sins I did and try to loose myself from each of them to be free unto my God. By the blood of the Lamb of God, Jesus Christ, I am set free. But as He was raised from the dead He also conquered death and in doing so freed me and a couple of millions of others that will call upon His name. I am a slave and a servant to the most High God. And I am happy to be that. But by His grace and His grace I am also His child. Which makes me more than joyful.