(Kadamba Kanana Swami, 16 May 2013, Simhachalam, Germany, Srimad Bhagavatam 9.7.21)
Transcribed by Jnana-samudra das
Vedic culture has different levels of worship and the lowest level of worship is the Shakta (Sanskrit: Śākta). The Shakta’s are those who are trying to pacify the ghastly material energy by making offerings. In the Old Testament, you will see a description of how there was a prediction that in every family, a son would die but wherever they put the blood of a lamb on the doorpost, the Angel of Death passed by. Things like that are Shakta.
That is a Shakta idea – that somewhere up there, there is a blood-thirsty ruler and we must pacify him. If we don’t want him to take our blood, then we must give him other blood – and therefore, we sacrifice goats; we sacrifice chickens; we sacrifice buffalos; we sacrifice all kinds of creatures – 
and even sometimes human beings, with the idea to pacify those deities so that their thirst for blood will be finished and then we can live very peacefully.
So this is the idea of the Shakta. That’s why we see Durga worship like this – to pacify material nature. Kali worship – Kali is the same Durga but in her angry feature, in her aggressive feature – when material energy is at its most blood-thirsty feature. So therefore, we see that the goddess Kali is being worshipped with so many offerings of animals. This is considered to be the lowest level of god consciousness.