Continuing our look at Isaiah 58. Going on from Verse 4
 Indeed you fast for strife and debate, And to strike with the fist of wickedness. You will not fast as you do this day, To make your voice heard on high.
It would appear that the fasts that God’s people were doing were causing a lot of debate and quarrels instead of peace and prosperity. Maybe the people were not doing it with a humble heart but instead trying to big note themselves whilst they were fasting. Remember the example of the proud Pharisee in Luke 18:10-14. The lowly publican was justified whilst the proud Pharisee was not.
Remember also Mt 6:16 Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.
Prayer and fasting is to be done with a humble spirit.
Another reason why they may have had quarrels and strife when they fasted was because they were fasting for God to provide physical benefits such as a bigger ‘camel’, bigger tent, better job etc.
Personally I believe that God will only provide things which are in accordance with His word. He has promised to provide for our physical needs so we need to put spiritual needs before our physical needs. See Luke 12:22-31. But rather seek ye the kingdom of God; and all these (physical) things shall be added unto you.
By all means we should pray for God to bless us in a physical sense if it is absolutely necessary for our existence. Example is a house if we have no house, a job if we have no job etc. but our primary concern in prayer and fasting should be about our spiritual needs.
However, healing needs are one area of the physical that we are encouraged through the scriptures to seek the Lord in prayer and fasting. See Matt 17:14-21. Here the disciples are asking Jesus why they could not heal a person with an illness. v20 And Jesus said unto them, Because of your unbelief: for truly I say to you, If ye have faith as a grain of mustard seed, you shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you. v21 However this kind goes not out but by prayer and fasting.
Jesus was lamenting their lack of faith and so, I believe, He is saying here that prayer and fasting will increase their faith which will lead to them being able to heal the people that they are praying for.
Often we fall into the trap of thinking we have a healing (or physical) need therefore we will prayer and fast until the healing need is gone. When in reality it is we have a healing need therefore we will prayer and fast until our faith is built up and then the healing need is gone.
Prayer and fasting is about growing spiritually and growing our faith, even when a physical need is being prayed for.
The previous day’s message is here.
The next and final message is here.