The argument from beauty is perhaps my favorite apologetic argument. While very powerful, it is also one of the least used. Peter Leithhart expounds on the apologetics of beauty here, offering keen and valuable insight.

But if, as Augustine seemed to believe, man is created so as to respond to the beauty of God and His creation, then an apologetic that highlights the beauty that beckons us is perfectly practical. Another response would be to suggest that aesthetics is ultimately inseparable from rationality and ethics . . . Apologetics should indeed aim at conviction, for a Christian has always been and will always be a man or woman who, with the church throughout the ages, says “Credo” with sincerity. At the same time, apologetics can do no less than to solicit the Augustinian response as well: “Late have I loved you, beauty so old and so new: late have I loved you” (Confessions 10.27.38).