It would seem they did not "believe in their heart."
If you declare with your mouth, “Jesus is Lord,” and believe in your heart
that God raised Him from the dead, you will be saved. Romans 10:9
If you declare with your mouth, “Jesus is Lord,” and believe in your heart
that God raised Him from the dead, you will be saved. Romans 10:9
Some people are ten inches away from salvation.
For all practical purposes, they may appear to be believers; and may have even convinced themselves that they are going to heaven.