No human being, however elevated they may be, can come in direct contact with God. For God is an energy of such power that they would be instantly pulverised.

There must always be an intermediary between the Divine and human beings, and the angelic orders are these intermediaries: they transform and filter this power in such a way for it to reach humans without obliterating them.
Even though it is said in the Bible that God spoke to the patriarchs and the prophets, it was not in fact he who spoke to them, but a messenger – which is exactly what the word ‘angel’ means.

And even the word ‘spoke’ is inaccurate here.

An angel does not speak in the sense that to speak means to pronounce words; but its presence, through the power of its vibrations, brings enlightenment, an inner direction, it inspires a project that the prophet translates into words.

Omraam Mikhaël Aïvanhov