I personally feel that it would have been a different issue if Shri Modi would have inaugurated the function by just laying the foundation stone but he has gone a step ahead by participating in the Bhoomi Pooja which is surely a point that needs to be considered seriously.
Inaugurating a function, be it of any organisation, religious or otherwise, in his capacity as the Prime Minister of this country is acceptable but Bhoomi Pooja is certainly a religious ritual and while Shri Modi has every right to be part of it as an individual, it was certainly not appropriate of his position as the Prime Minister of this nation to do so. We should remember that the Supreme Court, in the final verdict in the Babri Masjid case, has categorically said that the Temple should be built by the Trust that is formed for the purpose thereby making it absolutely clear that Governments, State or Centre, should not be involved.
Though I don't think anyone can harm or put our secular structure to danger by this single act or part of a series of acts that we have been witnessing for some time now, it is certainly against the secular principles enshrined in the Constitution of India. Shri Modi may (?) also inaugurate the foundation stone laying ceremony of the Mosque (whether they will invite him is another question that also needs to be pondered upon) that is proposed to be built in Ayodhya but will he take part in the pre or post-religious rituals connected to the function? I don't think anyone will have a doubt. Every citizen of India has the right to believe and profess the religion he belongs to and our PM too, being primarily a citizen of India, is no exception; but as PM, he should be exercising some restraint in the interests of the nation.
India is still secular and will, hopefully, remain to be so so long as the rights ensured by our Constitution are not meddled with. The secularist principles enshrined in our Constitution are not so weak that it can lose its prominence just because our Prime Minister has allowed his personal interest to stand on a higher platform.
“It is better to change an opinion than to persist in the wrong one." – Socrates