There is a saying in Punjabi " Kutte di pooachh sar gai par wat nahin gaya ( Dog's tail is burnt but twist is still there)".
This is the mentality of these nastik kala afghani chelas.They have neither read dasam Granth sahib nor
have intellect to understand this.
Durga is supreme God for Hindu sect. But Guru sahib while taking the base story of Durga from purana altered her characterstics. She was not shown as God but a creation of akal Purakh.Hence dimensions of Durga are different in Dasam granth.
ਤੈ ਹੀ ਦੁਰਗਾ ਸਾਜਿ ਕੈ ਦੈਤਾ ਦਾ ਨਾਸੁ ਕਰਾਇਆ ॥
तै ही दुरगा साजि कै दैता दा नासु कराइआ ॥
O Lord! By creating Durga, Thou hast caused the destruction of demons.
ਤੈਥੋਂ ਹੀ ਬਲੁ ਰਾਮ ਲੈ ਨਾਲ ਬਾਣਾ ਦਹਸਿਰੁ ਘਾਇਆ ॥
तैथों ही बलु राम लै नाल बाणा दहसिरु घाइआ ॥
Rama received power from Thee and he killed Ravana with arrows.
Chandi di vaar
Dr Tarlochan singh who did reasearch on dasam granth and whose articles appeared in The sikh review in 1950s noted as below on this point.
The History and Compilation of the Dasm Granth (Part 2 - Philosophical Works) - Dr. Trilochan Singh
Quote
2. The second point of confusion is about some lines occurring at the end of Chandi Charitar giving the fruit of reciting the Chandi song.
These lines are:
a. First Chandi Charitar:
"For whatever purpose a person reads this life of Chandi, it shall definitely be granted to him."
b. Second Chandi Charitar:
"Even if a foolish person reads the life of Chandi, immense wealth will be bestowed on him. If a coward reads it he will be able to fight most bravely; if a yogi reads it he will attain siddhi and if a student reads it he will attain knowledge."
c. Third Panjabi version Durga ki var:
"He who recites Durga's life will not take birth again."
All these are not the opinions of Guru Gobind Singh. They are the opinions of the writers of the original which Guru Gobind Singh faithfully translated. To dissociate himself and his ideal from it, Guru Gobind Singh either added a short introduction or an epilogue to each of these versions of Chandi. Guru Gobind Singh's opinions, giving his own faith were:
(a) In the First Chandi Charitar he said:
deh siva bar mohe ehai, shubh carman te kabhu na taro, na daro ar so jab jae laro, niscai kar aprni jit karo, ar sikh hau apne hi man kau eh lalac hau gun tau ucro, jab av kd audh nidan banai at hi ran mai tab jujh maro
Give me this power, O Almighty: From righteous deeds I may never refrain, Fearlessly may I fight all the battles of life, Full confidence may I ever have In asserting my moral victories, May my supreme ambition and learning be To sing of Thy glory and victory. When this mortal life comes to a close May I die with the joy and courage of a martyr.
(

The second Chandi Charitar is a part of the Bachiter Natak Granth. The Bachiter Natak has a collective introduction in which Guru Gobind Singh repeatedly wrote that he did not believe in the worship of gods and goddesses. In verses 92 and 93 Guruji said, "It is through Thy power, O God, that Durga destroyed the demons like Sumbh, Nisumbh, Dhumer and Lochan, Chand and Mund. It is through Thy power, O God, that Rama destroyed Ravana." And he concludes, Also “so sahib pae kaha parvah rahi eh das tiharo—With such a supreme One as my Lord, what care I, Thy servant, for anything or anyone?"
In the next stanza Guruji commented on the avatars and goddesses who were instrumental in killing all these and said,
"Kahe ko kur kare tapasa inki kou kaudi ke kam na aihai—Why indulge ye in the futile worship of these deities? Their worship is not worth a kaudi (one-twentieth of a penny)
(
c) The third Panjabi version has a long introduction, a part which forms the national prayer. In it the Guru invoked the grace and blessings of God and the nine Gurus.
taihi durga saj kai daita da nas karaya, taitho hi bal ram lai nal bana dehsir ghaia, taitho hi bal krishan lai kans kesi pakad giraya, bade bade muni devte kai jug tini tan laia, kini tera nht na paya.
It is Thou who created Durga and had the demons destroyed, From Thee derived Rama all the strength to kill the ten-headed Ravana. From Thee derived Krishna all his strength to catch Kans by the hair and dash him to the ground. Great seers and sages in all ages strained hard in penance to know Thee. None, none has attained Thy end.
In these short prologues and epilogues Guru Gobind Singh made his own opinion about Durga quite clear. He took these figures simply as historical persons of note and nothing else.