faith

Now to the one who works, wages are not credited as a gift but as an obligation. However, to the one who does not work but trusts God who justifies the ungodly, their faith is credited as righteousness

Romans 4:4-5

Paul illustrates this idea with an example. A man who works has earned his wage as an obligation on the employer’s part. The employer pays the worker nothing until the payment has been earned through work, and when the obligation is paid, the employer has no obligation whatsoever to pay anything else. A gift is different, for it is given freely if it isn’t given freely, then it isn’t a gift. In the same way, grace is not earned by working because if it was it wouldn’t be grace; it would be a payment for services.