"In order to develop a motivation of compassion we must have tolerance, patience. In the practice of tolerance one's enemy is the best teacher. Your enemy can teach you tolerance whereas your teacher or parents cannot. Thus from this viewpoint an enemy is very helpful - the best of friends, the best of teachers. In my own experience, the period of greatest gain in knowledge and experience is the most difficult period in one's life. If you go along in an easy way, with everything okay, you will feel that everything is just fine. Then one day when you encounter problems you feel depressed and hopeless. Through a difficult period you can learn, you can develop inner strength, determination and courage to face the problem. Who gives you this chance? Your enemy.
..Compassion is the real essence of religion..I myself feel and also tell other Buddhists that the question of nirvana will come later. There is not much hurry. But if in day to day life you lead a good life, honestly with love, with compassion, with little selfishness: then automatically it will lead to nirvana. Opposite to this, if we talk about nirvana, talk about philosophy, but do not do much about day to day practice, then you may reach a strange nirvana but will not reach the correct nirvana because your daily practice is nothing. We must implement these good teachings in daily life."
Tendzin Gyatso, Kindness, Clarity, and Light, translated and edited by Jeffrey Hopkins (Ithaca, N.Y.: Snow Lion Publications, 1984), p. 12-14