Peter opens his second letter with these words:

May grace and peace be multiplied to you

He wishes for blessings for his readers using the Greek (grace) and Hebrew (peace) salutations. What a marvelous introduction to what follows!
But how does this come about? Here Peter launches out beyond any ordinary salutation saying,

Through the knowledge of God and of Jesus our Lord 

Thereby, he doesn’t leave us a vague hope of sorts—no, he gives direction as well: we can receive grace (unmerited favor, mercy, help) and peace (tranquility and well-being) through knowledge.
Ah . .  Christians need knowledge.  Probably one of the greatest lacks in our day is genuine knowledge.  Too many try to get along with a sheer paucity of it. How much knowledge do you have?
But it’s not just any old kind of knowledge he has in mind—what is in view is knowledge of God and His Son, Jesus Christ. First, the knowledge of the Gospel (how that Christ died for all those who would trust in Him as Savior) and then, knowledge of all the things that Jesus has commanded (Mt. 28: 20).
Have you even checked out the commands of Jesus? To go through these over a year or so in a Sunday school class would be following a truly biblical curriculum. Why not try it?