A principle is a principle and in no case can it be watered down because of our incapacity to live it in practice. We have to strive to achieve it, and the striving should be conscious, deliberate and hard.
The inner voice is something which cannot be described in words. But sometimes we have a positive feeling that something in us prompts us to do a certain thing. The time when I learnt to recognise this voice was, I may say, the time when I started praying regularly.