The best explanation I give for Buddhism compared to theistic faiths is that Buddhism is a practice of realization and theistic faiths are ones of revelation. They both have faith/belief. Faith means to have trust or confidence in. However, theistic faith is faith in a culture’s understanding of God and that they have received communications from that God as to the nature of being.
In Buddhism, we have faith in the teachings of a man (the Buddha) who has given us the tools to develop our own understanding of the nature of being.
This is the true purpose of the Kalama Sutta. Do not believe because of some external reason, but believe because you have put the tools to use and seen that it works. It is not a sutta to be skeptical in our thinking but critical in our thinking.
And thus, being a faith in a practice to understand human nature, Buddhism is never in contrast to a belief in God. Those that do not believe or question a world with a supreme creator are welcome, but do too are those who believe in God.
The only conflict is with those with a God faith whose doctrine and dogma prevent the compliment of meditation or the possibility that there is no eternal “I.” To this end, the conflict of fundamentalist Christianity and Buddhism isn’t about God or Jesus, but about the soul.
Many Christians whose faith is more liberal (e.g. belief that the Bible may be more allegorical and open for interpretation or debate) have found themselves practicing both Christianity and Buddhism without conflict. As Jesus said, “Render up what is to Caesar’s.” In other words, what they develop a Buddhist practice to develop the mind to be more compassionate and heedful and they develop their Christian faith to be more reverent and spiritually aware.
When the Buddha was asked about God, his questions were always answered in some form with another question, “Why is that an important question to you?” In one instance, when he was asked about the nature of the universe, he responded, “I teach the understanding of suffering and the cessation of suffering.” To that end, worrying about a question that could never be satisfactorily answered was a fetter to enlightenment. This may be seen as then a conflict to those of God-faith, but those who have a strong belief in God do not ask “who created the universe?”, because they believe their already know.
In addition, there are Christians who are not interested in Buddhist enlightenment but still practice Buddhism. They practice for self-awareness to compliment their faith. They practice for mental peace to compliment their spiritual peace.
For those Buddhists, like myself, who do not compliment their Buddhist practice with any other faith; I do not start my practice with no faith and meditate thinking “prove something to me.” I pay homage to the Buddha, Dhamma and Sangha. Then I start my practice with full confidence that the Buddha’s teachings are true and I will see progress. So far in my life, I have seen my own development and the fruits of my labor. This gives me more confidence to continue my practice.
Meanwhile, I welcome the Chris-Bu and Jew-Bu practitioners in my temple. They may not have the same goal as I do when practicing, but that is their path. Any practice that develops mindfulness, compassion, joy and unconditional kindness is a good one.