Hebrews 12:12-15 provides a great formula for developing Endurance (GRIT).

Heb 12:12 Wherefore lift up the hands that hang down, and the palsied knees;

Get Busy Working. cf. Eph 4:28

13 and make straight paths for your feet, that that which is lame be not turned out of the way, but rather be healed.

Read, Apply Psalm 119:105; Prov 6:23

14 Follow after peace with all men, and the sanctification without which no man shall see the Lord:

Increase in Love. 1Thess 3:1-12; 1Tim 2:1-8

15 looking carefully lest there be any man that falleth short of the grace of God; lest any root of bitterness springing up trouble you, and thereby the many be defiled;

Test all things. 1Thess 5:21

Along with it the writer provides a warner for lacking endurance.

LEST…

Turned away,

Healed,

No man will see the Lord,

falleth short,

bitterness to trouble you,

Defiled.

for an overview of the book of Hebrews.