Here’s an interesting question for you to ponder from Apprising Ministries. How can a book on "Christian" apologetics written by two members who firmly adhere to apostate Roman Catholicism end up being published by an evangelical "Protestant" publishing house? Shane Trammel has more:

The book, ‘Handbook of Christian Apologetics’ is said to categorize and summarize all major arguments for all the major Christian teachings. But be warned, this book is authored by two very dedicated Roman Catholics (Peter Kreeft & Ronald K. Tacelli). Of special interest in this volume is the unbiblical treatment of the doctrine of justification (salvation).

Mike Oppenheimer puts this Roman Catholic influence into perspective for you when he writes:

Mother Theresa practiced today’s open Catholicism “I love all religions. … If people become better Hindus, better Muslims, better Buddhists by our acts of love, then there is something else growing there.She upheld that there are many ways to God’: “All is God–Buddists, Hindus, Christians, etc., all have access to the same God.” (12/4/89 Time, pp. 11, 13) While we can agree to love all religions and people there is a vast difference as accepting them as valid.

Mother Teresa told everyone no matter what their religion:

If in coming face to face with God we accept Him in our lives, then we are converting. We become a better Hindu, a better Muslim, a better Catholic, a better whatever we are. … What God is in your mind you must accept” (from Mother Teresa: Her People and Her Work, by Desmond Doig, (Harper & Row, 1976), p.156)

Catholic apologist Peter Kreeft is certainly touts the same line when he says, “We can and should investigate and learn from the wisdom in other religions” (Peter Kreeft Ecumenical Jihad p.79). “Allah is not another God…we worship the same God”(Peter Kreeft Ecumenical Jihad p.30). “The same God! The very same God we worship in Christ is the God the Jews-and the Muslims-worship.” (Ibid. p. 160)

All Kreeft is doing is affirming the Catholic Catechism where it states “The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God, mankind’s judge on the last day” (pp. 242, 243) (Online source)