“Let there be one scripture only, one common scripture for the whole world - Bhagavad-gītā. Let there be one God for the whole world - Śrī Kṛṣṇa and one hymn, one mantra, one prayer - the chanting of His name and let there be one work only - the service of the Supreme Personality of Godhead.”
"ekaṁ śāstraṁ devakī-putra-gītam
eko devo devakī-putra eva
eko mantras tasya nāmāni yāni
karmāpy ekaṁ tasya devasya sevā"
JagadGuru Sri Adi Sankaracharya