One should not give up things easily and decide that to do them are impossible.
"One should not give up things easily"＝「簡単に物事を諦めてはいけない」
"and decide that to do them are impossible"＝「そしてそれらを実行するのは無理だと決めつけてはいけない」
Example in context:
"You haven't even tried it yet! Don't think that it's impossible when you haven't even given it any effort."
アメリカ合衆国 
