Acts 17: 27-28:
God did this so that men would seek him and perhaps reach out for him and find him, though he is not far from each one of us. 'For in him we live and move and have our being.' As some of your own poets have said, 'We are his offspring.' (NIV).
Paul is in Athens when he makes the above statements. He is preaching to a mixed crowd of people, which included Epicurean and Stoic philosophers (Acts 17:18).
Question: are we modern-day evangelical Christians equipped to do the same thing? It is possible that many Christians have disdain for human philosophy. Why discuss the feeble reasoning of human philosophers when we have the wisdom and inspiration of Holy Scripture? It is like someone who owns a gourmet restaurant going outside to buy a hot dog from a street vendor.
We might remember that philosophers are people too. Their objections to God, their questions, and their lines of reasoning are all worthy of careful attention and discussion. Even as some of them object strenuously to God, they might, in their hearts, be hoping to be convinced that they are wrong. Some philosophers, moreover, are Christian, and try very hard to use the tools and language of philosophy to defend God.
George Berkeley (1685-1753) was an Irish bishop. While in his twenties, he wrote several philosophical works which were intended to defend God against the philosophical trends of his times. He is often grouped together with John Locke and David Hume as being a member of the empirical school of philosophy, which emphasizes the idea that all knowledge originates in experience, and in particular, sensory experience. Berkeley had a very unique vision of how our senses inform us. He believed that only mental phenomena exist. The physical or material world does not exist in the way that we normally think that it does. For example, if you stand too close to a fire, you will feel pain. But "pain" can only exist in the mind. So the fire and heat must also exist in the mind. Nothing can exist unless it is perceived, and all perception takes place in the mind.
Yes, this was and continues to be an unusual way of looking at things. But before we dismiss Berkeley as being a crackpot, we must realize that he also believed that since ideas and information and perceptions do not originate from our own minds, they must originate from God. Dave Robinson explains Berkeley's thinking as follows:
We can infer that God exists, even if we do not directly experience Him, because there has to be a non-material cause of our ideas. Fortunately, God is good, which explains why he provides our finite human minds with orderly sense experiences. He directly plants sensory ideas into our minds which are vivid, consistent and coherent. God also maintains sensory ideas for us to have when they are not being directly perceived.
While Berkeley's theories seem odd, his conclusions are positive towards God (unlike, for example, the ideas of David Hume, who was very much an atheist).
In Three Dialogues between Hylas and Philonous, Berkeley creates a long and extended dialogue between two parties where he explores these theories. Philonous is the proponent of Berkeley's philosophy and states:
To me it is evident, for the reasons you allow of, that sensible things cannot exist otherwise than in a mind or spirit, whence I conclude, not that they have no real existence, but that seeing they depend not on my thought, and have an existence distinct from being perceived by me, there must be some other mind wherein they exist. As sure therefore as the sensible world really exists, so sure is there an infinite omnipresent spirit who contains and supports it.
This sounds interesting, but even if we are trying to be sympathetic to Berkeley's ideas, we must ask, is he saying anything really new? He insists that he is, that his theories do not just acknowledge the existence of God, but tend to prove it:
Men commonly believe that all things are known or perceived by God, because they believe the being of a God, whereas I on the other side, immediately and necessarily conclude the being of a God, because all sensible things must be perceived by him.
Did Berkeley "prove" the existence of God? Well, no. For one thing, we know that the faith relationship is not intended to be utterly certain. Berkeley was provocative, however, and created a niche for himself in the history of philosophical ideas, a niche which honors God.
Let's look at one last extract of Berkeley's writings, where he re-states his basic principles and refers to Scripture:
... that there are only things perceiving, and things perceived; or that every unthinking being is necessarily, and from the very nature of its existence, perceived by some mind; if not by any finite created mind, yet certainly by the infinite mind of God, in whom we live, and move, and have our being.
It is never a waste of time to contemplate the mystery and grandeur of God.
In faith and fellowship,
 Dave Robinson, Bill Mayblin, Introducing Empiricism (Thriplow: Icon Books Ltd., 2004): 68.
 Robinson, p.69.
 A.A. Luce, T.E. Jessop, eds., The Works of George Berkeley Bishop of Cloyne (London: Thomas Nelson and Sons Ltd., 1949): 212.
 Luce and Jessop: 212.
 See Steven Law, The Great Philosophers (London: Quercus, 2007):91.
 Luce and Jessop: 236.