[23] And whatever you do, do it heartily, as to the Lord and not to men,
It's probably safe to say that we all default (at least a little) to "selfish" service. Our (sinful) human nature steers us all in that direction. If I do this, they will do that. I work to get paid. I pay my bills to keep my stuff. I do a lot out of obligation.
Some of the greatest blessings we will ever experience will come from selfless, God-honoring service. Doing for those who cannot do for us. This is answering the call to be the hands and feet of Jesus... for the glory of God and not for selfish gain.