They knew what was going on when the mark began to burn and they weren't surprised by its reaction. They knew that it was a sign that they had done something that doesn't align with the oath they took when they became lamp bearers.
It is a warning for now. The burning brand won't let them sleep or have peace of mind because of what they have done. This is to give them the opportunity to rectify their offense and correct their mistakes.
But the consequences will get worse if they continue to ignore the warning. The pain will get so bad that they will be tortured by it day and night. Soon it will get so bad that they will be doing anything to resolve it or kill themselves to end the pain.
This is the foundation of the lamp bearers as an organization. Every member of the group has to be upright and uphold the laws of righteousness, or they will be held accountable.
