My experience is that anything less than 100% commitment in principle to serving God not self will gradually degrade. The 1% reservation gradually infects and spreads through the rest. Practice can sometimes slip, but the commitment must be 100% in principle.
When I catch myself with divided loyalties, I make a list of areas of my life, and ask God for the sane and sound ideal for each (a simple bullet-pointed list of attitudes and actions). I write down the answers. I then get on with it.