He hailed the fact that in India, believers and atheists as well as "those believing in idol worship" and "those opposing the idol worship" co-exist peacefully.
Mr Modi said that ultimately, all religions, faiths, ideologies or traditions give the message of peace, unity and goodwill.
"Greetings on the start of Ramzan. May this holy month enhance the spirit of togetherness, peace & harmony across the world," he tweeted this morning.
Greetings on the start of Ramzan. May this holy month enhance the spirit of togetherness, peace & harmony across the world.- Narendra Modi (@narendramodi) May 28, 2017
Later, in his monthly radio programme 'Mann Ki Baat', Prime Minister Narendra Modi said, "I convey my hearty greetings to everyone in India and elsewhere in the world, especially the Muslim brethren at the advent of the auspicious month of Ramzan."
He noted that prayers, spirituality and charity are accorded the highest priority during the month of fasting.
"We Indians are very lucky that our ancestors have created such a tradition that today India and its 1.25 billion people can take pride in the fact that people from all communities and faith are available here," Mr Modi said.
"We have adapted ourselves to the myriad kinds of ideologies, different ways of worshipping and all types of traditions and imbibed the art of co-existential living," he added.
He expressed confidence that the holy month would be helpful in further strengthening these values of peace, unity and goodwill.