Why do we expect preachers to practice what they preach? It is in our benefit to absorb what we think is right and good, and follow it in our lives. How does it matter
whether the person conveying it to us follows his word or not. It only becomes relevant if we do not want to use our own intellect to judge and decide whether the teachings are right or wrong. We need some model to be followed blindly, without appl
ying our mind. It is in this situation that we need the preacher to practice what he preaches before we can follow him/her.
When someone tells you to quit smoking, it is nice if he doesn't smoke himself but it should not be a prerequisite. It is for your benefit he is advising you. Take it or leave it. You are seeking an advice to improve your life, not the preacher. He should (normally) not have any personal interest in improving your quality of life.
One does not have to be a Sadhu to be eligible to advise.
मुफ्त के ज्ञान में कोई if या but नहीं होता। लेना है तो लो, नहीं तो आगे बढ़ो।
Free knowledge is unconditional (like love). Take it, or leave it.