The evil that is annihilated by Kalki avatar at the end of kali Yuga are the negative forces of nature working within us all the time. At any given moment of life human beings invoked both positive and negative thoughts. Positive thoughts precipitated into Amrita (the elixir of life) and negative forces into Vish (poison) that accumulates in the body.
Negative forces propel human beings towards indulgence in vice. Instead of lessening, negative forces give a firm footing to our ego (Aham in Hinduism). Presence of ego takes a human being further and further away from spirituality. To practice spirituality rightly we have to demolish our ego in totality. This can be accomplished by overpowering negativity within in totality.
Negativity in a human being is not that easily demolished, destroyed forever. Otherwise every human being could reach stage of self realization, god realization in no time.
Demolition of ego occurs in stages. Overpowering five senses and mind in stages, controlling our desires and wishes we can demolish our ego in totality. Positivity, indulgence in positive thinking helps us scale higher levels of spirituality whereas negativity brings us down.
Mounted with jnana wisdom of Bhagavad Gita, Kalki avatar would show to mankind the merits of indulgence in teachings of sacred texts of Hinduism. After all we are a spirit, a soul atman manifesting human form. We were never a human being in flesh manifesting a soul atman. As a spiritual traveler we can reach our true inner self, become a pure soul atman only by indulging in spirituality, never path of rituals (path of religion).
Indulgence in path of jnana yoga in present Kali Yuga is an absolute must to cut, demolish darkness of ignorance within. The same could not be accomplished indulging in bhakti yoga or karma yoga alone. The darkness of ignorance can be cut only by light of jnana wisdom.
In present Kali Yuga, the sermon of Bhagavad Gita by Lord Krishna has a major role to play. Other than scriptures of Hinduism like Bhagavad Gita and Upanishads (independent spiritual treatises) nothing in this world can lead mankind towards Satyuga, the golden period.
Dominated by ego (Aham within) we failed to recognize presence of spirit, soul existing in heart. Spirituality was all about demolition of ego in totality. Only then we could hear sweet small promptings of soul atman coming from within our heart. Allegorically the spirit, soul atman existing in our heart is Lord Krishna.
If we do not indulge in spirituality in present life time, we would keep rotating in endless cycles of birth and death again and again. To emancipate forever from cycle of birth and death, our indulgence in teachings of spirituality contained in Bhagavad Gita is an absolute must.
kalki will destroys demon kali,spirits,ghost and evil