Here the prashad (Food offered, consecrated by the word of their scripture)is prepared in the langar kitchen. Prashad is blessed by offering of Ardas, a prayer, often before reading a hukam from the Guru Granth Sahib. To **perform the blessing during the recitation of Ardas:****The Sikh touches the kirpan to the prashad, passing the steel through it, at the appropriate moment of Ardas, just prior to its conclusion.Guru Nanak Sahib Ji is not a human but is in fact Shabad (Divine Infinite Wisdom).A Sikh worships only the ‘One God’ and bows his or her head only to the Shabad (Infinite Divine Wisdom ,Book ,Scripture ) which took the form of Ten Nanaks and was recorded in writing, which is the Sikh Guru today – Sri Guru Granth Sahib Ji, the revealed Divine Word of God.
Here idols can be anything a book their scripture,falsely called wisdom of divine knowledge,persons,they believe in incarnation of persons,etc satanic wisdom,James 3:15 This wisdom is not such as comes down from above, but is earthly, unspiritual, devilish.Psalms 95:5 For all the gods of the Gentiles are devils: but the Lord made the heavens.
2 Thessalonians 2:2-11 Let no one deceive you in any way; for that day will not come, unless the rebellion comes first, and the man of lawlessness is revealed, the son of perdition, 4 who opposes and exalts himself against every so-called god or object of worship, so that he takes his seat in the temple of God, proclaiming himself to be God. 5 Do you not remember that when I was still with you I told you this? 6 And you know what is restraining him now so that he may be revealed in his time. 7 For the mystery of lawlessness is already at work; only he who now restrains it will do so until he is out of the way. 8 And then the lawless one will be revealed, and the Lord Jesus will slay him with the breath of his mouth and destroy him by his appearing and his coming. 9 The coming of the lawless one by the activity of Satan will be with all power and with pretended signs and wonders, 10 and with all wicked deception for those who are to perish, because they refused to love the truth and so be saved. 11 Therefore God sends upon them a strong delusion, to make them believe what is false,
Acts 15:28 For it has seemed good to the Holy Spirit and to us to lay upon you no greater burden than these necessary things: 29 that you abstain from what has been sacrificed to idols and from blood and from what is strangled and from unchastity. If you keep yourselves from these, you will do well. Farewell.”Acts 21:25 But as for the Gentiles who have believed, we have sent a letter with our judgment that they should abstain from what has been sacrificed to idols and from blood and from what is strangled[c] and from unchastity.
1 Corinthians 10:20 No, I imply that what pagans sacrifice they offer to demons and not to God.
From the Council of the Apostles this has not been changed,that you abstain from food offered to idols.this is nothing to do with people, culture, or celebrations but it is regarding food offered to idols.