The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance. 

So then, dear friends, since you are looking forward to this, 

make every effort to be found spotless, blameless and at peace with him. 

Bear in mind that our Lords patience means salvation, 

just as our dear brother Paul also wrote you with the wisdom that God gave him. 2Peter 3:9,14-15