The world is full of sorrow and strife; man tries to avoid these and somehow derive a little joy and peace, in the midst of grief and disappointment. It is like digging a well in a sand heap; the deeper you dig, the faster it caves in. And, the whole process has to be repeated again. The piles of sensual desires overwhelm the aspirant and drag him down into grief. The only means of getting lasting joy is bhakti; that is the best among the yuktis (the paths dictated by intelligence). That alone gives the shakti (the strength needed for acquiring unshakable joy).
Bhakti can grow only on prepared ground. The method of preparation is given in the Vedas, which speak also of things that have to be avoided. The Vedas lay down the lines of conduct, the method of living, the ideals to be followed. You may not all be able to study the Vedas and grasp the meaning. But those who have studied and who are following the teachings and who are overcome by the joy of that experience are here to tell you, in terms that you can understand.
The four Purusharthas (goals of human life), as mentioned in the Bhagavad Geeta, which itself is the essence of the Upanishads, is in the latter part of the Vedas called Vedanta. Of these goals, the final consummation is moksha that is the very crux of the problem of life. Moksha means liberation from bondage to both joy and grief, which are the obverse and reverse of the same coin. Moksha is the recognition of the truth; but, though it is so simple, it required the cultivation of viveka, vairagya and vichakshana (discrimination, detachment and ability), to know the Truth and escape from the temptation to hug falsehood. Viveka is necessary to decide what is dharma---the very first of the Purusharthas. Each one must decide for himself the dharma he must choose for his uplift; this requires viveka, the recognition of the permanently beneficial source of pure and lasting joy. (SSS Vol.4)