If you remove the mandalas, mantras, and unusual deities from Vajrayana, one central question remains:
Why does a person practice any of this at all?
The traditional answer is: to reduce suffering and help others.
What Does Compassion Mean Here?
In Buddhism, compassion is not simply pity.
It is the intention that another person be free from suffering and from the causes of suffering. And this concern is not limited only to people we like or feel close to. Ideally, it extends to all beings.
For example, imagine that someone behaves aggressively.
The automatic reaction might be:
“He is terrible. I hate him.”
Compassion practice asks us to look more deeply:
“What is causing this person to act this way? Fear? Anger? An inability to deal with their own emotions?”
This does not mean excusing harmful behavior. A person can set clear boundaries while still not wishing suffering on someone else.
Where Does Tantra Fit Into This?
This is where the logic becomes clearer.
Imagine that a practitioner visualizes themselves as a compassionate deity, recites a mantra, and imagines helping other beings.
Without compassion, this could become little more than an elaborate fantasy.
That is why traditional Vajrayana places great importance on bodhicitta before advanced Tantric practice — the intention to attain awakening in order to become better able to benefit others.
In other words, mantra, mandala, and visualization are tools.
Compassion answers the question of what those tools are for.
Without it, Vajrayana can easily look like a collection of exotic techniques.
With compassion, its underlying logic becomes much simpler:
First, learn to become less controlled by your own fear, anger, and self-centeredness — and then use the attention and freedom that creates to relate to others more skillfully.