These four thoughts turn our minds away from worldly preoccupations, and towards the Dharma -
namely, the Buddhist teachings, and the practice of them, in order to prevent us from experiencing future suffering. These four thoughts are:
Thinking about our precious human life, and what it can achieve.
Thinking about impermanence, and the inevitability of death.
Thinking about karma, how our actions affect our future.
Thinking about the uncertainty, the problems, the suffering, and the happiness that never lasts, throughout uncontrollably recurring rebirths, samsara.
Chamtrul Rinpoche will speak about how by having these four thoughts, we start to realize this precious and rare opportunity that we have, and as a result, we turn our minds to the Dharma.