According to the Lamrim, there are four reasons, why the Buddha is worthy to be a refuge. Meaning, why we can rely and entrust the Buddha. Let’s review them to see what makes Buddha the unique and ultimate teacher of all.
First, he has mastered himself and attained the sublime state of fearlessness. If you have not attained this, he would not be able to protect others from all fears, just as a person who has already fallen down cannot help up someone else who has fallen down.
Second, he is in all ways skilled in the means of training disciples. If he were not so, he would not able to fulfill your needs, even if you went to him for refuge.
Third, he has great compassion. If he did not have it, he would not protect you even if you went to him for refuge.
Fourth, he is pleased, not by material offerings, but by offerings of practice. If he were not, he would not act as a refuge for everyone, but would help only those who had previously helped him.
In brief, only one who is free of all fears, who is skilled in the means of freeing others from fear, who has great, impartial compassion for everyone, and who acts for everyone’s welfare regardless of whether or not they have benefited him, is worthy of being a refuge.
Since only the Buddha has these qualities, and the divine creator and so on do not, thus, the Buddha alone is the refuge, of all beings.
Therefore, his teaching, and the community of his disciples, are also worthy of being a refuge. Thus, after you have ascertained these things, entrust yourself to the three jewels with a single-pointed focus. Develop this certainty from the depths of your heart, for, once you are able to do this, they cannot fail to protect you.
This is so because there are two possible causes of we are being protected: an external and an internal.
The Teacher has already fully realized the external factor or cause, but we suffer because we have not yet developed the internal factor, entrusting ourselves to the refuge.
~ Words of wisdom from master Tsongkhapa.