Hebrews 10:35-39

So do not throw away your confidence; it will be richly rewarded.  You need to persevere so that when you have done the will of God, you will receive what he has promised.  For in just a very little while, 

"He who is coming will come and will not delay.  But my righteous one will live by faith.  And if he shrinks back I will not be pleased with him."  

But we are not of those who shrink back and are destroyed, but of those who believe and are saved.