Timing the market is a very enticing proposition. It is seductive to think that if one can find the tops and the bottoms of the market, then one can make supernormal returns. There are charting approaches, wave theories and a bunch of other stuff to predict the market. However most of the academic research on such 'publicly' known theories indicates that the returns after costs is lower than passive investing.
Note the word public. There maybe investors out there who have systems to predict the market and make a killing. Well, they are not going to disclose that anytime soon.
So for the common investor, we have the option to either use publicly known systems knowing that the academics may very well be correct and use it till we can prove them wrong. The other option is to develop your own systems, which yield excess returns.
The same argument can be applied to value investing. Academic say it is not possible as the market is efficient.
My own journey has been of a skeptic, to a tentative believer to a firm believer. I read about value investing almost 10-12 years back. It made a lot of sense, but I am not one to have blind faith. I was not ready to invest money in any approach till it worked for me. As a result I read books on value investing and on the efficient market hypothesis too. At the same time I started applying the principles with my own money, but on a very small scale. As my returns have outpaced the market, my confidence has grown to a point where this is the only approach for me and a majority of my funds are invested via this philosophy.
So value investing is not some religion to which I got converted one fine day. I started as a tentative believer and have got convinced as I saw my own results.