Scripture answers this with a method instead of a figure, and the method is unusually
specific.
Decide in advance. The amount is purposed in the heart before the offering arrives, which
is the difference between generosity that lasts and generosity that depends on mood. Make
it proportional. Paul tells each believer to set aside a share as he has prospered, so the
gift scales with income by itself and a raise raises it without a new decision. Give it
first. The firstfruits language means counted off the top, not skimmed from what survived
the month, because what survives the month is usually nothing. And give it cheerfully:
under compulsion is explicitly ruled out.
Two stories set the range. A widow puts in two small coins and Jesus says she gave more
than the wealthy donors, because the measure is what it cost her, not what it totalled.
And churches in deep poverty gave beyond their ability and begged for the privilege, which
makes a percentage a floor, not a ceiling.
One common way to put it into practice: pick a number you can start this month without shame about its size, write it
as a percentage, give it before anything else clears, and raise it a point whenever your
income rises. The percentage that is still being given in the twelfth month is the one that
was set honestly in the first.
The passages
Printed in full from the public-domain World English Bible, resolved from a local copy of
that text before this page was built. Read them before you take our summary on trust, and
see how we read Scripture on money for the ten rules
every page here follows.
1Now concerning the collection for the saints, as I commanded the assemblies of Galatia, you do likewise. 2On the first day of the week, let each one of you save, as he may prosper, that no collections be made when I come. 3When I arrive, I will send whoever you approve with letters to carry your gracious gift to Jerusalem. 4If it is appropriate for me to go also, they will go with me.
41Jesus sat down opposite the treasury, and saw how the multitude cast money into the treasury. Many who were rich cast in much. 42A poor widow came, and she cast in two small brass coins, which equal a quadrans coin. 43He called his disciples to himself, and said to them, “Most certainly I tell you, this poor widow gave more than all those who are giving into the treasury, 44for they all gave out of their abundance, but she, out of her poverty, gave all that she had to live on.”
1Moreover, brothers, we make known to you the grace of God which has been given in the assemblies of Macedonia; 2how that in much proof of affliction the abundance of their joy and their deep poverty abounded to the riches of their generosity. 3For according to their power, I testify, yes and beyond their power, they gave of their own accord, 4begging us with much entreaty to receive this grace and the fellowship in the service to the saints. 5This was not as we had expected, but first they gave their own selves to the Lord, and to us through the will of God. 6So we urged Titus, that as he had made a beginning before, so he would also complete in you this grace. 7But as you abound in everything, in faith, utterance, knowledge, all earnestness, and in your love to us, see that you also abound in this grace. 8I speak not by way of commandment, but as proving through the earnestness of others the sincerity also of your love. 9For you know the grace of our Lord Jesus Christ, that, though he was rich, yet for your sakes he became poor, that you through his poverty might become rich. 10I give a judgment in this: for this is expedient for you, who were the first to start a year ago, not only to do, but also to be willing. 11But now complete the doing also, that as there was the readiness to be willing, so there may be the completion also out of your ability. 12For if the readiness is there, it is acceptable according to what you have, not according to what you don’t have. 13For this is not that others may be eased and you distressed, 14but for equality. Your abundance at this present time supplies their lack, that their abundance also may become a supply for your lack; that there may be equality. 15As it is written, “He who gathered much had nothing left over, and he who gathered little had no lack.”
9Honor Yahweh with your substance, with the first fruits of all your increase: 10so your barns will be filled with plenty, and your vats will overflow with new wine.