I’ve heard some people, even influential people, say that it’s not necessary to have a Guru. I respectfully disagree.
In the field of Yoga, where one is seeking to know the ultimate mystery of life, even an expert teacher isn’t enough.
Teachers teach techniques, but reaching beyond the mind to know Providence itself requires more than techniques. It requires grace—and only one who has attained oneness with the Infinite can be a channel for such grace.
One need not spend much time with the Guru; teachers can take one most of the way. But the Guru has an indispensable role.