While all sentient beings without exception possess the Buddha nature, they do not realize this. The mind of most sentient beings is clouded by habitual thought patterns and obscurations accumulated over countless lifetimes. In order to connect with our Buddha nature – the deepest level of consciousness – we need to purify the coarse mental accumulations. The practice of Vajrasattva is the most powerful purification meditation in the Tibetan Buddhist tradition. It is practiced as part of the preliminary sequence of practices in all tantric lineages of Tibetan Buddhism.
Sincere practice of Vajrasattva can purify even the most severe karmic traces. There are four powers that are essential in this practice: power of support, power of remorse, power of resolution, and power of action as an antidote. The power of support in this context means turning to Vajrasattva for help in the purification. It is the belief that Vajrasattva can help us purify obscurations and that is why we engage in the Vajrasattva visualization and mantra recitation. The power of remorse describes the sincere regret of wrong thoughts, speech and actions we have done. The power of resolve means that we make a firm decision not to engage the wrong actions, thoughts and speech again. The power of action as an antidote means that we start engaging in activities that are the opposite of the wrong things we have done. The teachings list engaging in the practice of Vajrasattva and resting in the nature of mind as the most powerful antidotes to bad karma.

Visualization for the practice of Vajrasattva:
Refuge and motivation: At the beginning of the practice we take refuge in the enlightened Buddhas, Dharma and the Sangha. We acknowledge that we will do the Vajrasattva practice in order to purify our obscurations and those of all sentient beings so that we all can attain full complete enlightenment as quickly as possible.
Resting in the Buddha nature: Now we settle our mind in its natural state.
Visualization and the main practice: From the purified self-recognizing awareness we visualize a lotus flower on the top of our head and inside the lotus flower is a shining moon disk. On the moon disk appears a double vajra and iside the vajra is the syllable HUNG. The vajra and the syllable HUNG are of bright white color radiating light. The syllable and vajra suddenly transform into bright white Vajrasattva with his consort surrounded by a hallo of bright light. In the heart chakra
of Vajrasattva is the syllable HUNG inside the vajra. One can visualize his/her root guru in the Vajrasattva form. As we start reciting the mantra of Vajrasattva the syllables of the mantra are circling clockwise around the HUNG in the vajra in the heart chakra of Vajrasattva. As they are moving they radiate powerful bright light that reaches all sentient beings and as it touches them all their obscurations are purified. All sentient beings are transformed into the Vajrasattva deity and recite the Vajrasattva mantra in unison. As the mantra circles in the heart chakra of Vajrasattva bright white nectar and light flow from Vajrasattvas heart chakra and enter your body through the opening on the top of our head where the bones of scul connect. The light and nectar spread through our body and purify all the sickness and obscurations of body, speech and mind. Your become the Vajrasattva. Then you disolve into self-recognizing awareness.
Disolving the visualization: All sentient beings in the form of Vajrasattva transform into light and this light returns into the heart chakra of Vajrasattva. Vajrasattva and his throne suddently disolve into light and this light disolves into the syllable HUNG at the heart chakra of Vajrasattva. Finally, the syllable HUNG disolves from bottom up into a small sphere of light and this sphere of light enters your body as a blessing of Vajrasattva.
Resting in the Buddha nature: Now we settle our mind in its natural state again.
Dedication: Dedicate the merit of the practice so that your negative karma and the karma of all sentient beings would be swiftly purified and you and all sentient beings would recognize their Buddha nature and attain enlightenment in this lifetime.

The 100 syllable Mantra of Vajrasattva:
OM VAJRASATTO SAMAYA MANU PALAYA VAJRASATTO TENOPA TITSA DRIDO ME BHAVA SUTO KAYO MEBHAVA SUPO KAYO MEBHAVA ANU RAKTO MEBHAVA SARVA SIDHI ME PRAYATSHA SARVA KARMA TSUTSA ME TSITAM SHRI YANG KURU HUNG HAHA HAHA HO BHAGHAVAN SARVA TATHAGATA VAJRA MAME MUTSA VAJRA BAWA MAHA SAMAYA SATO AH HUNG PHAT

Short Vajrasattva mantra:
OM VAJRASATTVA HUNG