There is a great article that illustrates the concept of grace written by Charles Stanley.
“One of my more memorable seminary professors had a practical way of illustrating to his students the concept of grace. At the end of his evangelism course he would distribute the exam with the caution to read it all the way through before beginning to answer it. This caution was written on the exam as well. As we read the test, it became unquestionably clear to each of us that we had not studied nearly enough.
The further we read, the worse it became. About halfway through, audible groans could be heard through out the lecture hall. On the last page, however, was a note that read, "You have a choice. You can either complete the exam as given or sign your name at the bottom and in so doing receive an A for this assignment."
Wow? We sat there stunned. "Was he serious? Just sign it and get an A?" Slowly, the point dawned on us, and one by one we turned in our tests and silently filed out of the room.
When I talked with the professor about it afterward, he shared some of the reactions he had received through the years. Some students began to take the exam without reading it all the way through, and they would sweat it out for the entire two hours of class time before reaching the last page.
Others read the first two pages, became angry, turned the test in blank, and stormed out of the room without signing it. They never realized what was available, and as a result, they lost out totally.
One fellow, however, read the entire test, including the note at the end, but decided to take the exam anyway. He did not want any gifts; he wanted to earn his grade. And he did. He made a C+, but he could easily have had an A.
This story illustrates many people’s reaction to God’s solution to sin. Some people look at God’s standard - moral and ethical perfection - and throw their hands up in surrender. "Why even try?" they tell themselves. "I could never live up to all that stuff."
Others are like the student who read the test through and was aware of the professor’s offer but took the test anyway. Unwilling to simply receive God’s gift of forgiveness, they set about to rack up enough points for their works with God to earn it.
But God’s grace truly is like the professor’s offer. It may seem unbelievable, but if we accept it, then, like the stunned students who accepted the professor’s offer, we, too, will discover that, Yes, God’s grace truly is free. All we have to do is accept it.
"For by grace are you saved by faith; and that not of yourselves. It is the gift of God; not of works, lest any man should boast." (Ephesians 2:8-9)