Complex sentence: In 2007, Gurmeet Ram Rahim Singh hurted the religious sentiments of the Sikhs, when he dressed similar to tenth Sikh Guru, Guru Gobind Singh.Following protests from Sikhs he sent an apology to Akal Takht Sahib, that was rejected by Supereme Sikh body.
Split into simpler sentences: In 2007, Gurmeet Ram Rahim Singh hurted the religious sentiments of the Sikhs, when he dressed similar to tenth Sikh Guru, Guru Gobind Singh. He then sent an apology to Akal Takht Sahib, that was rejected by Supereme Sikh body.