Is there one thing that must be avoided at all costs if we are to achieve spiritual enlightenment?

To forget yourself, to become detached from your very being is surely a way to stop your progress. To switch off the light within yourself will halt your progress and stop your awareness and stop your growth and grind you to a standstill, until you become aware again of the love within yourself, the potential you have for going forward and the light and love that awaits you.

Keep your switch on my friend, this way you will not stop.