Contradiction with Proverbs 27:1
"Boast not thyself of to morrow; for thou knowest not what a day may bring forth." - This verse warns against boasting about the future, while 2 Corinthians 1:14 speaks of confident boasting.
Proverbs 27:1: Boast not thyself of to morrow; for thou knowest not what a day may bring forth. [to...: Heb. to morrow day]
Contradiction with Matthew 6:34
"Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself." - This verse advises not worrying about tomorrow, contrasting with 2 Corinthians 1:14's forward-looking confidence.
Matthew 6:34: Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day [is] the evil thereof.