Dharma Samabhava as a strategy against conversion is a great failure
and can leave Hindus defenseless against conversion efforts.
Missionary groups can simply quote Hindu praise of Christ or the Bible,
of Mohammed, the Sufis and the Koran, to convince Hindus that
their religion is also good. They can tell Hindus that since Hindus
believe all religions are the same they should not object to Hindus
converting to other beliefs. In other words it only gives the clever
missionaries more ammunition. "After all," they say,
"you respect our religion. Why not then join it?"
Hindu votaries of Sarva Dharma Samabhava pride themselves in
supporting other religions. They tell a Christian to be a better
Christian or a Muslim to be a better Muslim, and would not encourage
them to become Hindus, as if these religions contain the same
teachings and have the same value as Hinduism. This they think is
being liberal in religious matters and will aid everyone in their
quest for God. However, it only consigns people to the limitations
of their religious beliefs as these actually are, not as they are
idealized to be.
A religion that does not recognize Self-realization,
God-realization or have any yogic sadhana, such as most Western
religions have been historically, cannot lead people to Moksha in
the Hindu sense. If one wants to help a person to find Moksha, which
should be one's real Dharmic concern, it is better to tell them to
follow what is true, to seek out the Dharma, even if it may require
going against their religion of birth.