2 Corinthians 8:3-4

‘For according to their power, I bear witness, yes and beyond their power, they gave of their own accord, beseeching us with much entreaty in regard of this grace and the fellowship in the ministering to the saints.'

For they gave as much as they could afford, indeed more than they could afford, and they not only did it freely, they actually begged to be allowed to give it in order to serve those in even greater need than themselves. This suggests that at first Paul was reluctant to take it from them in view of their own extreme poverty. But the grace of God was so at work within them and they so longed to have their part in serving the needy saints of God, that they insisted vigorously. Their spirit was that of the widow whom Jesus praised in the Temple (Mark 12:41).

‘The fellowship in the ministering to the saints.' ‘Fellowship' means sharing in common. ‘Ministering' is diakonia, acting in service. They wanted to show themselves a part of the worldwide church, and a part that truly served and worked as one with all.