Answer:
The full quote of Mark Twain is:
"“When in doubt tell the truth. It will confound your enemies and astound your friends.”
Explanation:
Mark Twain's religious beliefs had certain elements of Christianity also. According to Christian's Holy Bible God hates liar.
"Proverbs 12:22
The LORD detests lying lips, but he delights in people who are trustworthy."
So Twain in his quote is also emphasizing the importance of speaking truth. Whatever the situation may be speaking truth will gain us friends.
