I thought this was a decent illustration on the topic of grace, sanctification, good works, and reward.
“An awkward schoolboy has to make a speech before a strange audience. It is a difficult task, and he does not even know how to begin. All his own efforts are useless. Then his father calls him and says: ‘If you commit this little speech which I have prepared, and recite it without missing a word, it will be a success.’ And the boy obeys. There is nothing of himself — it is all his father’s work; he merely believes that what his father has prepared for him is good. And in this confidence he goes before the strange audience, delivers his father’s composition, and succeeds. However, the writing of the speech did not end the matter, and it could not be ended until the boy had done his part. When God has prepared the good work for us, the matter is not ended until we do what God has prepared for us.”
“Coming home the boy does not proudly ask a reward, but with gratitude he embraces his father for his love and faithfulness. Having obtained success, God’s children are profoundly thankful for their Father’s excellent help; and they acknowledge that they owe it all to Him. And if He is pleased to give them a reward, it is not because they have deserved it; for if it were a question of desert, the children would have to give everything to the Father! But it is merely a reward of love for the future support of their faith.”