Proof of God?

I just read a passage in the Letter to Diognetus, and I think it's worth reproducing here:

Writing about Christians...

"[Dost thou not see] them thrown to wild beasts that so they may deny the Lord, and yet not overcome?

Dost thou not see that the more of them are punished, just so many others abound?

These look not like the works of a man; they are the power of God; they are proofs of His presence."

Do I live such that I am a proof of God?