Usually it's something like "Well, I've read bits of it."
"How long ago?"
"Well, it's some years ago. But. . . the Bible does have contradictions in it. . . doesn't it?"
Well actually, no. If you looked, you might find something that looked like a contradiction to someone who didn't understand what he was reading and was only looking for an excuse not to believe. The remarkable thing is that the Bible was written by about 40 different people in different places and different walks of life over a period of something like 1,600 years, and it all agrees.
You can see the Persian empire, the empire of Alexander the Great, the Roman empire, the coming of Christ, all prophesied there many years before they happened. You can see prophecies in the Old Testament fulfilled in the New Testament in exact detail. In the Old Testament, written hundreds of years before Christ came, there are hundreds of detailed prophecies about Him in His life and His death.
Psalm 22 foretells His physical suffering on the cross; how His hands and His feet were pierced; how He was mocked and insulted, even to the words of His mockers; how they cast lots for His clothing. Psalms 22 and 31 foretell the words He spoke on the cross. Psalm 34 tells how none of His bones were broken. Psalm 69 tells how in His suffering they gave Him vinegar to drink.
Zechariah tells how He would be betrayed for 30 pieces of silver. Isaiah 53 tells in advance how He was led like a lamb to the slaughter, how He was wounded for our transgressions and bruised for our iniquities, how after His death He was placed in a rich man's grave.
But don't take my word for it. The Bible doesn't need me to defend it. Check it out for yourselves.