This is not ambition and greed, but the power to persevere without fear.
In spite of all obstacle and failure, the scientist persevere with his experiment.
What we all respect and admire is the person who can stand up against overwhelming difficulties and persevere without an answer.
We should persevere with the fight against corruption, one of the fundamental principles for governing a country.
If you persevere with the work, you'll succeed in the end.
Sir Alex Ferguson is to persevere with Ben Foster in goal for Manchester United despite his erratic form while deputising for the injured Edwin van der Sar.
It's difficult, but I'm going to persevere with it.
You have to persevere with difficult students.