Luke 13:24
Strive to enter in through the strait gate; for many, I say to you, will seek to enter in, and shall not be able.
Hebrews 4:11
Let us earnestly strive, therefore, to enter into that rest, lest any one fall after the same example of unbelief.
Hebrews 6:11-12
But we desire every one of you to show the same diligence, in order to have your hope fully assured to the end:
2 Peter 1:5
so, even for this very purpose, uniting to these things all diligence, add to your faith, virtue; and to virtue, knowledge;
2 Peter 1:10
Wherefore, brethren, give the greater diligence to make your calling and election sure: for if you do these things, you will never fall.