Christ's promise and Christians' endurance

Keep the word of Christ and His apostles who wrote the New Testament. 

That is the task for every Christian. 

"Amen, amen, I say to you: if anyone keeps My word, he will never see death." (John 8:51)

"If they kept My word, they will keep yours also." (John 15:20)

Christians must therefore hear the entire New Testament and commit their hearts to keeping the word that they hear there. This is a task that requires effort, even endurance. 

Why endurance? It's not because the New Testament is a very long text. Rather, there are many temptations to fail at keeping the word of Christ and His New Testament apostles.

For example:
(1) Bad translations of the New Testament, which create contradictions between different parts of the text.

(2) Bad summaries of the New Testament, which may leave out parts of the text or even misrepresent the entire text!

(3) Bad traditions among Christians, which mislead people away from keeping the word of Christ and His New Testament apostles. 

These temptations must be endured.

"Blessed is a man who endures temptation, because having become approved, he will receive the crown of life that He promised to those loving Him." (James 1:12)