dis·ci·pline (ds-pln)
Yes it does benefit us, whether that is our intention or not. If it is done to the Glory of God it cannot help but benefit us.
If we resist the temptation to eat food during a fast, this will enable us to more easily reist other temptations that come to us outside our control. If we learn to give freely to God we will be more likely to give freely to men. While we are to do it to the glory of God, there will be spiritual rewards which come from it. Any time we give glory to God we reap rewards.
Discipleship is training-not sacrificing. You will find more mileage with the "sacrifice of praise" then you will with training. That is because the ONLY thing we can offer to God is our praise. Everything else comes from God.
If we resist the temptation to eat food during a fast, this will enable us to more easily reist other temptations that come to us outside our control.
And right here is the problem with this whole thing. If we resist this will enable us to... Where precisely are we depending on the Lord? We are solely dependent upon Christ our Lord, day by day, through all circumstances. Without Christ, we can do nothing.
Everything God instructs us to do benefits us. Everything. That's one of the perks of being among His flock. All things work for our welfare.
When we really stop to realize what this means, it's awesome indeed. God has planned everything, the good and the bad, for our benefit -- to strengthen us, to instruct us, to protect us, to correct us, to love us. I think we are loved more than we can ever imagine or articulate.