George Campbell on Evidence for Christianity

"God has neither in natural nor in revealed religion left himself without witness; but has in both given moral and external evidence, sufficient to convince the impartial, to silence the gainsayer, and to render inexcusable the atheist and the unbeliever. This evidence it is our duty to attend to, and candidly to examine. We must prove all things, as we are expressly enjoined in holy writ, if we would ever hope to hold fast that which is good."

—George Campbell
A Dissertation on Miracles, Introduction (p. 12)