Does Deuteronomy 12:30 forbid Christian apologetics toward other religions since we can’t inform ourselves about them?  Does the verse apply for learning about other religious practices as a whole or simply forbid taking part in the practices of other religions?

This passage appears to be a command to not even learn about other religions.  I can certainly see how it raised this question for you.  However, I believe that the command is to avoid syncretism.  Syncretism is the practice of combining practices of various religions in one’s religion.  What I mean is this.  God is telling his people to avoid unhealthy curiosity about the religious practices of their neighbors.  In other words, do not show interest in their religious practices for ourselves.  Do not inquire of them in order to consider how they might not be in opposition to the Law of Moses.  Do not include portions of other religions in your worship of YHWH.  Do not incorporate their sacrifices in your practice and do not include their gods in your pantheon.

The same would apply to Christians.  It is not a sin to learn about Islam or Hinduism or any other religion, but we should not “dabble” in these religions.  We should not do a comparative study of other religions with the aim to decide where other religions might be competitors to Christianity—to find portions of other religions which we could include in our Christian practice.  I read the writings of atheists, of Calvinists, of Muslims, of Buddhists and Hindus, but I always look at them through the lens of Christianity, knowing that the Bible is absolutely and without reservation the Word of God, and therefore, by definition. other supposed Scriptures are not true, though they may contains elements which are true.  I do not practice yoga, as it is, in essence Hinduism.  I do not adopt the meditative practice of Sufis or Buddhists.  I do not use the ying/yang symbol and I do not bring the religious symbols of other religions into my home.

The key part of this passage is this: we should not say “We will do the same.”  This commandment is against syncretism. Syncretism is the practice of combining the practices or beliefs of various religions to form a cafeteria-style religion.  One Christian group which has taken part in considerable syncretism is the Roman Catholic Church which purposefully allowed native groups in Africa, Central and South America in particular, to include certain of their pagan practices in their Catholicism. The Catholic Church also incorporated religious symbolism and church festivals from pagan European religions.  They “baptized” certain pagan gods into a sort of Christian pantheon.  The worship (or more accurately veneration) of Mary is one such example, as it is a concession, in part, to the Mother Goddess worship of so many pagan religions.

My conclusion is that Deuteronomy 12:30 is a commandment that Jews not be involved in syncretistic inclusions of pagan religions into their worship of YHWH.  It is NOT a commandment against learning facts about these religions. If we want to refute Islam, Hinduism, Buddhism, New Age of any other religion, we must learn about these religions.  However, in learning we must not incorporate subtle elements of these religions into our worship of God, even if we find some practices to be attractive to us.

I have published a book about other worldviews/religions which delves in-depth into the belief systems/ world views of all the important world religions.  It is True, Right Better: A Defense of the Christian Worldview.  It is available at www.evidenceforchristianity.org

John Oakes