I just read this and thought it to be a beautifully eloquent and forceful defense of theism:

Transcript of the Pope's Regensburg address, September 12th, 2006:

We believe in God. This is a fundamental decision on our part. But is such a thing still possible today? Is it reasonable? From the Enlightenment on, science, at least in part, has applied itself to seeking an explanation of the world in which God would be unnecessary. And if this were so, he would also become unnecessary in our lives. But whenever the attempt seemed to be nearing success - inevitably it would become clear: something is missing from the equation! When God is subtracted, something doesn’t add up for man, the world, the whole vast universe. So we end up with two alternatives. What came first? Creative Reason, the Spirit who makes all things and gives them growth, or Unreason, which, lacking any meaning, yet somehow brings forth a mathematically ordered cosmos, as well as man and his reason. The latter, however, would then be nothing more than a chance result of evolution and thus, in the end, equally meaningless. As Christians, we say: I believe in God the Father, the Creator of heaven and earth - I believe in the Creator Spirit. We believe that at the beginning of everything is the eternal Word, with Reason and not Unreason. With this faith we have no reason to hide, no fear of ending up in a dead end. We rejoice that we can know God! And we try to let others see the reasonableness of our faith, as Saint Peter bids us do in his First Letter (cf. 3:15)!

We believe in God. This is what the main sections of the Creed affirm, especially the first section. But another question now follows: in what God? Certainly we believe in the God who is Creator Spirit, creative Reason, the source of everything that exists, including ourselves. The second section of the Creed tells us more. This creative Reason is Goodness, it is Love. It has a face. God does not leave us groping in the dark. He has shown himself to us as a man. In his greatness he has let himself become small. Whoever has seen me has seen the Father, Jesus says (Jn 14:9). God has taken on a human face. He has loved us even to the point of letting himself be nailed to the Cross for our sake, in order to bring the sufferings of mankind to the very heart of God. Today, when we have learned to recognize the pathologies and the life-threatening diseases associated with religion and reason, and the ways that God’s image can be destroyed by hatred and fanaticism, it is important to state clearly the God in whom we believe, and to proclaim confidently that this God has a human face. Only this can free us from being afraid of God - which is ultimately at the root of modern atheism. Only this God saves us from being afraid of the world and from anxiety before the emptiness of life. Only by looking to Jesus Christ does our joy in God come to fulfilment and become redeemed joy. During this solemn Eucharistic celebration, let us look to the Lord and ask him to give us the immense joy which he promised to his disciples (cf. Jn 16:24)!