Never think, “Even though I have confidence in the Three Jewels, it is not really certain that this work will be accomplished.” Instead, one should know that the Enlightened One is surely able to protect those who surrender and act in accord with his words, because the Enlightened One is endowed with the transcendental wisdom which knows all the paths of practice that are in harmony with the intelligence and nature of all living beings, because he has the compassionate desire to establish his disciples on the right path after turning them from wrong ways, and because he has accomplished the two accumulations of merit and transcendental wisdom and has accomplished the resolve to help beings. So even though one has not yet attained liberation from worldly existence, it is one’s fault for not having trusted and not having acted in accord with the words of the Three Jewels, not because the Three Jewels have no compassion.
In brief, those who do not entrust themselves to the Precious Jewels, who are arrogant and who assume they are intelligent have no certainty in accomplishing their schemes. Even if they are accomplished, it is not certain whether those schemes will turn out well in the long run. So it is important to entrust oneself always to the Precious Jewels.
From Three Visions: Fundamental Teachings of the Sakya Lineage of Tibetan Buddhism by Ngorchen Konchog Lhundrub, pages 16-17