Buddha is the unexcelled Teacher who reveals to us the path of inner development. The path is the holy Dharma that Buddha taught. The Sangha can be anyone, lay or ordained, who has entered into that path. Buddha is the one who shows us the path, not the one who takes us on the path. As the Buddha himself said,
You must take yourself on the path.
Having entered the path of the holy Dharma, you must become able to protect yourself; you must become your own refuge. Buddha said,
I have shown you the path to Liberation,
but understand! Liberation depends on you.
Likewise Buddha said:
Buddhas to not wash away sins with water,
They do not remove beings sufferings with their hands,
Nor do they transfer their realizations to others;
By showing them the reality of nirvana, beings are liberated
Written by Khenpo Karten Rinpoche, an excerpt from his book Precious Teachings, the chapter “Purpose and Benefits of the Holy Dharma,” page 87 in the paper book, and page 94 in the online pdf.