The main practice of the Mahayana is Bodhicitta, which is the essence of the churned milk of the Holy Dharma. If there is no Bodhicitta, your practice, whether Sutra or Tantra, will be as 'essenceless' as a banana tree. Not only that, you should also remember that, wherever space pervades, there are sentient beings (who are searching for happiness). One's own rebirths, taken sequentially, are beginningless, and so we have had parents countless times. Each sentient being has been our mother and father innumerable times, and so, the amount of benefit we have received from them is inconceivable. Therefore, we should meditate on Love and Great Compassion for all sentient beings: enemies, friends, relatives and strangers. Develop equilibrium which is free from holding some close with desire and others distant with anger. By thinking with a good heart of the benefits of others, you must use your body, speech and mind to practice virtue, always making special and noble prayers.

-- Jamyang Khyentse Chokyi Lodro