Yet they seek Me day by day and delight to know My ways, as a nation that has done righteousness and has not forsaken the ordinance of their God. They ask Me for just decisions, they delight in the nearness of God.
"Why have we fasted and You do not see? Why have we humbled ourselves and You do not notice?"
Behold, on the day of your fast you find your desire, and drive hard all your workers. You fast for contention and strife and to strike with a wicked fist. You do not fast like you do today to make your voice heard on high.
Is it a fast like this which I choose, a day for a man to humble himself? Is it for bowing one’s head like a reed and for spreading out sackcloth and ashes as a bed? Will you call this a fast, even an acceptable day to the Lord?
Is this not the fast which I choose: to loosen the bonds of wickedness, to undo the bands of the yoke, and to let the oppressed go free and break every yoke? Is it not to divide your bread with the hungry and bring the homeless poor into the house; when you see the naked, to cover him; and not to hide yourself from your own flesh? Isaiah 58:2-7 NASB
Fasting, as generally understood in religious circles, is an act of self-sacrifice that prepares the one fasting to receive or achieve some spiritual gain. Truthfully, I've never understood such thinking because it seemed to suggest to me that God was somehow impressed with or benefitted by us starving ourselves. As if asking and seeking in prayer might get a response from God, but fasting in a suitably impressive enough demonstration of self-denial is bound to elicit a return call from God. Can spiritual things be that mechanical?
Tithing is promoted, really, along similar lines. If we ask God to provide, he may, but if we tithe he's virtually obligated to! Giving up things we have, things that could benefit us, in order to establish a divine line of credit doesn't seem at all spiritual to me. It's mercenary, manipulative and flesh-catering. I don't buy it one bit! Besides, is either action self-denial if undertaken in order to bring a reciprocal benefit? Would that not be akin to loving those that love us?
If the example of Christ and the words of Isaiah teach us anything about the subject, self-denial actually has to be selfless. I know Jesus endured the cross and its shame for the joy set before him, but that joy was founded in someone else being benefitted. It's not like anything we do, or our life and death, or even our salvation adds anything to God. Self-denial in this regard can only mean losing the personal benefit of what you have available to you so that someone else benefits instead.
Giving, fasting, or any act of self-denial does not rise to the threshold of notice if it is undertaken with a mind to boomerang a benefit back to self. Such acts are not godly nor god-like, just self-centered and selfish. Jesus said his disciples would fast after he was taken from them. I've got to believe he did not have in mind the fasting chosen by the Pharisees, but rather, the fast that God chooses.