I hope this is helpful for your friend. It sounds like he was raised with a literalistic view of Genesis being six literal days. If so, I understand his dilemma. Hopefully, this will help him look beyond his old Sunday School classes :-). It is a big topic and one that is debated. I will try not to be too wordy and complicated, but also not too simple to insult his intelligence.

There are those who hold a literal six days of creation that took place 6,000 years ago and thus we have a “young earth.” Other Christians hold a view that God created over a long period of time and the “days” of Genesis refer to time periods and explained in a way that pre-scientific people could understand.

Intelligent design means that even though God may have used evolutionary processes to develop the world, nature and man, it was done over time by his design, not by chance.

God has two books: 1) he wrote nature which we can “read” and 2) he wrote Divine Revelation in Scripture and Tradition which we can also read. Since he is truth his two “books” cannot contradict each other so science and revelation, faith and reason, are not opposed to each other. Divine Revelation explains the why and Natural Revelation (science) tries to explain the how.

Assuming as most Catholics do, that God created over a period of time, it takes scientific discovery into account. There have been ice ages and periods of a warm earth. This is why the whole global warming agenda today is silly since these cycles have happened throughout the earth’s long history without man and there is very little man can do to cause them now. We know there were times the earth was very warm because we find warm-blooded creatures frozen under the ice in the north. So, we have to take science into account and figure out how science and revelation fit together.

Having said that, even in the Genesis creation account, man is created last as God’s masterpiece. Already in the early days of creation there were plants and animals. We are not told the kind or names of the animals, only that there were those that flew, swam, walked and crept about. We assume that the animals are those that we know today, but there could very well have been at one time or another dinosaurs and other creatures that preceded man.

 Hairy mammoths and other extinct animals have been found in the ice and also dinosaur bones and fossils. It is no problem for a Christian who looks at science and the Bible to say, “God worked over time and there were stages and phases to the process of creation. There was a time before man was actually created in the likeness of God that dinosaurs roamed the earth.” What happened to wipe them out is a whole other discussion.

What we as Catholics (and other Christians) must believe is that God created everyone out of nothing (ex nihilism) by his power. Second, that “life” was a unique creation of God and third, that at one point in time God created man and woman as a uniqued creation and embed them with his own likeness and image with an eternal soul. How and when that happened is left open for discussion.

What any person would be foolish to do is deny God’s existence because if there is no personal infinite God then we are all just a random process of chemicals, time, chance and matter. In this case there is no meaning or purpose to existence and someday it will all collapse in on itself and it will be over, just one big meaningless nightmare.

Or to believe that a God exists and to ignore him is to be foolish and miss out on the great adventure of knowing him and learning about his creation and deeper life and the ultimate meaning and love of God.