Hebrews 10:29

29So think about a person who has turned against the Son of God. That person's punishment will surely be much worse! He says that Christ's sacrifice has no value for him. He has made God's new covenant seem like something bad. It was Christ's death on the cross that made that person clean, so that he would belong to God. But now that person has insulted God's Spirit, who brings God's kind help to us.