You believe Avatars are incarnation of God and you worship them as such but the following is the counsel of Sikhi:
ਅਵਤਾਰ ਨ ਜਾਨਹਿ ਅੰਤੁ ॥ ਪਰਮੇਸਰੁ ਪਾਰਬ੍ਰਹਮ ਬੇਅੰਤੁ ॥1॥
Incarnated beings do not know His limit. The Transcendent Lord, the Supreme Lord God, is infinite. ||1|| (Guru Granth Sahib Ji, Ang 894)
ਜੁਗਹ ਜੁਗਹ ਕੇ ਰਾਜੇ ਕੀਏ ਗਾਵਹਿ ਕਰਿ ਅਵਤਾਰੀ ॥ ਤਿਨ ਭੀ ਅੰਤੁ ਨ ਪਾਇਆ ਤਾ ਕਾ ਕਿਆ ਕਰਿ ਆਖਿ ਵੀਚਾਰੀ ॥7॥
In each and every age, He creates the kings, who are sung of as His Incarnations. Even they have not found His limits; what can I speak of and contemplate? ||7|| (Guru Granth Sahib Ji, Ang 422)
ਕੋਟਿ ਬਿਸਨ ਅਵਤਾਰ ਸੰਕਰ ਜਟਾਧਾਰ ॥ ਚਾਹਹਿ ਤੁਝਹਿ ਦਇਆਰ ਮਨਿ ਤਨਿ ਰੁਚ ਅਪਾਰ ॥
Millions of incarnations of Vishnu and Shiva, with matted hair yearn for You, O Merciful Lord; their minds and bodies are filled with infinite longing. (Guru Granth Sahib Ji, Ang 455)
ਦਸ ਅਉਤਾਰ ਰਾਜੇ ਹੋਇ ਵਰਤੇ ਮਹਾਦੇਵ ਅਉਧੂਤਾ ॥ ਤਿਨ੍ ਭੀ ਅੰਤੁ ਨ ਪਾਇਓ ਤੇਰਾ ਲਾਇ ਥਕੇ ਬਿਭੂਤਾ ॥3॥
There were ten regal incarnations2 of Vishnu; and then there was Shiva, the renunciate. He did not find Your limits either, although he grew weary of smearing his body with ashes. ||3|| (Guru Granth Sahib Ji, Ang 747)
ਬਿਨ ਕਰਤਾਰ ਨ ਕਿਰਤਮ ਮਾਨੋ ॥ ਆਦਿ ਅਜੋਨਿ ਅਜੈ ਅਬਿਨਾਸੀ ਤਿਹ ਪਰਮੇਸਰ ਜਾਨੋ॥1॥ ਰਹਾਉ ॥
Except Waheguru (God), do not accept anyone as the ruler and controller of the world. The one who has been here from the beginning, the one who is away from births, the one who is matchless, and the one who cannot be destroyed, know that He is Waheguru (God). (Shabad Hazaray, Guru Gobind Singh Ji)
ਸੋ ਕਿਮ ਮਾਨਸ ਰੂਪ ਕਹਾਏ ॥ ਸਿਧ ਸਮਾਧ ਸਾਧ ਕਰ ਹਾਰੇ ਕਯੋਹੂੰ ਨ ਦੇਖਨ ਪਾਏ॥1॥ ਰਹਾਉ ॥
How can we accept God coming into this world in human form? The Siddhas (people who try to attain spiritual powers by living in jungles) are tired by sitting with their eyes closed to find and see God but are been unable to. (Shabad Hazaray, Guru Gobind Singh Ji)
ਕਾਹੂ ਨੇ ਰਾਮ ਕਹਯੋ ਕ੍ਰਿਸ਼ਨਾ ਕਹੁ ਕਾਹੂ ਮਨੈ ਅਵਤਾਰਨ ਮਾਨਯੋ ॥ ਫੋਕਟ ਧਰਮ ਬਿਸਾਰ ਸਭੈ ਕਰਤਾਰ ਹੀ ਕਉ ਕਰਤਾ ਜੀਅ ਜਾਨਯੋ ॥12॥
Someone calls him Ram or Krishna and someone believes in His incarnations, but my mind has forsaken all useless actions and has accepted only the One Creator. ||12|| (33 Sawayeas, Guru Gobind Singh Ji)
ਦਸ ਅਵਤਾਰ ਅਕਾਰ ਕਰ ਏਕੰਕਾਰ ਨ ਅਲਖ ਲਖਾਯਾ ॥
Ten incarnations also flourished but none could perceive ek-ankar, the supreme Lord. (Bhai Gurdas Ji, Vaar 16)
Hindu: If in your religion you do not accept Avatars as incarnations of God, and their worship is not accepted, then why the following is written in the Dasam Granth?
ਮਥਰਾ ਮੰਡਲ ਕੇ ਬਿਖੈ ਜਨਮ ਧਰਿਓ ਹਰਿਰਾਇ ॥3॥… ਜੇ ਨਰ ਸਯਾਮ ਜੂ ਕੇ ਪਰਸੈਂ ਪਗ, ਤੇ ਨਰ ਫੇਰ ਨ ਦੇਹ ਧਰੈਂਗੇ ॥2483॥
Hari Rai took birth in the surroundings of Mathra….He who worships the feet of Krishna will never take birth again. (Krishna Avatar)
There are other stories that prove that the tenth Guru believed in Avatars.
Sikh: Krishna Avatar is only the translation of hindu historical texts. From the translation3 and explanation of historical texts and Puranas one cannot say that this is the counsel of Guru Gobind Singh Ji to the Sikhs. Concerning religion, writings of the Guru are Jaap Sahib and Sawayeas. There in is only greatness and praise of the Eternal and the Avatars are described as servants of the Lord.
Hindu: In Guru Granth Sahib there as a panegyric hymn where it is advised to meditate on the names of all Avatars, such as:
Madhusudan, Damodar, Rikhikesh, Krishan, Murari…(Maru Solhe, Ang 1082)
Sikh: Dear Hindu brother, Guru Arjan Dev Ji has presented his belief at the end of the hymn which you think is in praise of Avatars. The Guru says:
ਕਿਰਤਮ ਨਾਮ ਕਥੇ ਤੇਰੇ ਜਿਹਬਾ ॥ ਸਤਿ ਨਾਮੁ ਤੇਰਾ ਪਰਾ ਪੂਰਬਲਾ ॥
With my tongue I chant the Names given to You. 'Sat Naam' is Your perfect, primal Name.
It means that Hari (Waheguru) has existed without change through all the four Yugas. Guru Nanak Dev Ji explains:
ਆਦਿ ਸਚੁ ਜੁਗਾਦਿ ਸਚੁ ॥ ਹੈ ਭੀ ਸਚੁ ਨਾਨਕ ਹੋਸੀ ਭੀ ਸਚੁ ॥1॥॥
True In The Primal Beginning. True Throughout The Ages. True Here And Now. O Nanak, Forever And Ever True. ||1||
There are many names in Gurbani (hymns of the Gurus) which are connected with specific Avatars and gods but the Guru has the same name in various contexts to refer to One God4. It is evident that from this many, without understanding, get lost and miss the essence of Gurbani. In the following hymn Rama and other names are used for actual personalities.
..ਹੋਰ ਕੇਤੇ ਰਾਮ ਰਵਾਲ ॥
There have been many Ramas and lesser beings.
ਰਾਮੁ ਗਇਓ ਰਾਵਨੁ ਗਇਓ ॥
Rama has gone. Ravana has gone.
ਕੇਤੇ ਕਾਨ ਮਹੇਸ ॥
Gone are many Maheshas and Krishnas.
In some of the following these names refer to the Supreme Lord.
ਰਮਤੁ ਰਾਮ ਸਭ ਰਹਿਓ ਸਮਾਇ ॥
Rama (transcendent) is in everyone.
…ਟੇਕ ਏਕ ਰਘੁਨਾਥ ॥
Repair to the refuge of One Raghunath (Lord).
…ਹਰਿ ਜਪੀਐ ਸਾਰੰਗਪਾਣੀ ਹੇ ॥
Contemplate Hari, the real Sarangpani.
1. In Sikh religion, there is no condemnation of any Avatar o prophet and there is no attempt to give the deficiencies of any person. This is the advice: God is above death and birth and is worthy of adoration. Prophets are all working in His will.
2. Fish, Tortoise, Vairah, Lion, Bawan (Dwarf), Budha, Parasram, Ram Chandra, Krishna and Kalki.
3. In Dasam Granth the Tenth Master has rendered the story of Bhagauti in Vernacular.
"There is no other desire, O Lord, only wish to fight for Dharma." (Krishna Avatar)
4. In the same way previously Allah was the name of an old idol. The English word 'God' was used by Teutons to mean Dieu. When Teutons adopted Christianity 'God' came to mean the Eternal. Jehovah is also such a word, which is used by Jews to designate God, but it was the Name of a special god of Assyria. In the same way there are numerous names in other religions.