Antonia —

I'm not sure this is what you are specifically looking for, but the Handbook of Catholic Apologetics by Dr. Peter Kreeft and Ronald Tacelli is a good book for understanding:

• why we believe what we believe as Christians and Catholics
• what the arguments are
• how to defend the faith against the claims of other religions
• and so forth.

It does discuss other religions, but mostly in general terms; it doesn't teach you specifically how to refute Buddhism or Hare Krishnaism etc. or give a lot of historical information about them but it does tell you how to prove Christianity in general. The idea that matter is evil is a very old one called Gnosticism so if you can find texts that discuss this subject, they may be helpful.

With the exception of Islam and its offshoots (Sufism, the Druze, and the Bahai faith), a few minor religions, and quasi-Christian groups (like Mormonism, Jehovah's Witnesses, Christian Science, and Unitarians), none of the major world religions separated from the faith God founded; rather, they developed in a vacuum. This is true of:

• Hinduism
• Buddhism
• Hare Krishnaism
• Confucianism
• Taoism
• Shinto
• Sikism
• Jainism
• Zoroastrianism
• animist religions
• and so forth.

For historical context, I suggest starting at the entry World Religions in Wikipedia and then branch out to the individual religion pages.

I seriously doubt you'll find any substantive information specifically refuting the Hare Krishnas against Christianity, mostly because they are such a small group and don't respond well to reason and argument. They are rooted in Hinduism, so studying apologetics against Hindus may prove helpful, but I don't think the Hindus are Gnostic like your friend, so you may have a special case.

Fundamentally, the truth of Christianity is rooted in the historical fact that:

• Jesus lived
• performed miracles
• died, and rose from the dead
• validating His claims to be God.
  
  
• You might ask them if their religion is rooted in miracles, or whether it is divinely revealed and, if so, how they know it is divinely revealed?

Explain that there are demonic spirits that would seek to deceive us and lead us away from the truth, so it is important to know the source of our truth and verify its authenticity. You might point to miracles in the Catholic Church, such as those of St. Pio in the middle of last century (within memory):

• who could read souls (that is, he knew people's sins without their telling them)
• had miraculous wounds of Christ
• had people visit him from Purgatory
• and so forth.

I met a man who was miraculously and instantly cured of a debilitating spine injury due to the intercession of Blessed John Henry Newman. His miracle was the cause for his beatification and was thoroughly verified by even non-Catholic doctors as being medically inexplicable.

Anyway, hopefully that is a start.

Eric