Where in this passage does it say a Christian who continues willfully sinning will receive a reward.
1 Corinthians 3:12-15
Now if anyone builds on the foundation with gold, silver, precious stones, wood, hay, straw— each one's work will become manifest, for the Day will disclose it, because it will be revealed by fire, and the fire will test what sort of work each one has done. If the work that anyone has built on the foundation survives, he will receive a reward. If anyone's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.
Where does it say here if a Christian willfully sins he will receive punishment-
Hebrews 10:26-27
26 If we deliberately keep on sinning after we have received the knowledge of the truth,no sacrifice for sins is left, 27 but only a fearful expectation of judgment and of raging fire that will consume the enemies of God.