Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 2
If you want to change, you must first resolutely get rid of the defects of your vital being, persevering steadily, however difficult it may be or however long it may take, calling in always the divine help and compelling yourself always to be entirely sincere.
As for fitness and unfitness, nobody is entirely fit for this Yoga; one has to become fit by aspiration, by abhyāsa, by sincerity and surrender. If you have always desired the spiritual 
life, it is the psychic part of you that desired it, but your vital has always come in the way. Establish a sincere will in the vital; do not allow personal desires and demands and selfishness and falsehood to mix in your sadhana; then alone the vital in you will become fit for the sadhana. Lately you seem to have made a more sincere endeavour; if you want it to succeed, the endeavour must become always purer and more steady and persistent. If you practise sincerely, you will get the help needed by you.
If you take the right attitude in your work, that itself will bring the help. The right attitude is to work for the sake of the Divine, as an offering, without demand for any reward, without selfish claims and desires, without self-assertion and arrogance, not quarrelling with your fellow workers, thinking it to be the Mother’s work and not your own, and trying to feel her power behind the work. If you can do that, your nature will progress and change.
I write this much in answer to your letter because I find in it a beginning of vital sincerity which was not there before. The rest depends upon you. If you become vitally sincere, the help will be with you.