qualification of a guru to initiate a mantra to his disciple is that the guru himself has practised same mantra and attained \'siddhi\'. the indication of \'siddhi\' is that guru\'s balanced lifestyle which is visible to us.
similarly the suggestion that comes out of experience has more impact and should be followed, rather than a suggestion given out of bookish/internet knowledge
well said sushma it shows clearly when people are asked to do simple math and they just look for calculators in their mobile phone rather than use brain or use pen and paper. everything is now instant ! instant food, instant love, instant life