The master Vimalamitra says:
Out of fear and mindfulness of the qualities we go.
The reason one needs to go for refuge is that one is subject to fear. When one has nothing to fear and is free to make one’s own choices and decisions, one obviously does not need to seek protection from anyone.
However, since time without beginning we have been lost in the darkness of ignorance, imprisoned in the fearful dungeon that is cyclic existence, and from this nothing except the Three Precious Jewels is able to protect us.
So it is in order to be protected from such fear that we go for refuge, keeping in mind their qualities in having the power to protect us.
There are three kinds of individuals who go for refuge.
Beings of modest capacity take refuge as if to acquire an escort, through fear of the lower realms and a desire to obtain, as a result, the happiness of the higher realms. Their principal motives are this fear and desire. The “family” to which such individuals belong includes Buddhists and non-Buddhists, whether or not they adhere to a particular philosophical school.
Beings of middling capacity take refuge out of fear of cyclic existence and a desire to attain, for themselves alone, liberation in the blissful state of nirvana. In addition to fear and desire, their principal motive is faith. They belong to the families of Listeners and Solitary Realizers.
Beings of greater capacity take refuge because they are afraid of samsara and nirvana, and because they wish to attain the non-dwelling state beyond suffering [that is, the nirvana that is beyond the extremes of samsara and nirvana (or “existence and peace”]. In addition to fear, desire, and faith, their principal motive is compassion. They belong to the family of the Great Vehicle.
As we read in the Lamp for the Path,
Know that those who strive,
By any means, and for their own sake,
Simply to be happy in cyclic existence
Are beings of the lowest capacity.
Those who turn their backs on happiness in cyclic existence
And draw away from evil deeds,
Who merely strive for their own peace,
Are known as middling beings.
Those who, through the suffering they have understood in themselves,
Yearn for the complete exhaustion
Of all the suffering of others —
Such beings are supreme.
There is another reason for taking refuge, as Lord Atisha points out:
All may have the vows
Excepting those who have not taken refuge.
In other words, the refuge is the indispensable basis for all vows. Buddhists and non-Buddhists are classified as such according to whether or not they have taken refuge, and without having taken refuge there is no way one can be freed from cyclic existence.
Inferior refuges include inanimate things such as mountains and fortresses, powerful nonhuman beings such as gods, and rulers and other influential human beings. Because they are unable to protect us from cyclic existence, they are inferior objects of refuge, for they themselves have not gained freedom from the prison of cyclic existence.
The objects of refuge for those who strive for complete liberation are the Three Jewels. The Three Jewels have the power temporarily to protect us from the fears of cyclic existence and ultimately to establish us in ultimate excellence, and they are therefore an infallible refuge, for as the Great Master has said,
Samsaric lords, however good, will let us down.
As objects of refuge, the Three Jewels will never fail.
Source: Rinpoche, Dudjom. A Torch Lighting the Way to Freedom (pp. 139-141). Shambhala. Kindle Edition.by