Ok, I admit that “prove” here won’t be in the Cartesian, 100% without-a-doubt, sense that many empiricalists in our culture think is required before we can reasonably be said to “know” something is true. However, this time-tested argument will help you show your non-believing neighbor that your belief in God is not an irrational leap of faith.
This argument is simple and based on natural revelation which means it doesn’t require the other person to accept the authority or validity of the Bible beforehand. Interestingly enough, this also means that this argument isn’t the exclusive domain of Christianity. While it doesn’t point to a specific God, it does help establish the basis for the belief in God which is one of the biggest barriers to belief in our postmodern, philosophically naturalistic culture.
This arguement has origins with Aristotle‘s arguement of the Prime Mover and as omnious as it may sound the arguement is quite effective, in part, for its simplicity. The general argument goes as follows:
1. Everything that begins to exist has a cause
2. The universe began to exist1
3. Therefore the universe had a cause
That’s it! There are obviously points to be made at each step to support and bolster each claim, but the general outline ought to be enough to answer a fundamental question of human existence that philosophical naturalism is at a loss to answer which is: Why is there something rather than nothing?
This argument is heavily promoted by Dr. William Lane Craig and has been used with devastating effectiveness in many debates. For further reading on the subject I highly recommend visiting his site, reasonablefaith.org, for his free, in-depth, lectures. I also recommend his book “Reasonable Faith” where, in addition to the Kalam Cosmological Argument, Dr. Craig also explores several variations on the parent Contingency Argument and refutes some objections raised by noted theoretical astrophysicist, Stephen Hawking.