“Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.”  
2 Peter 1:4

The word ‘partakers’ is from the Greek ‘koinonos’ which means, ‘associate, sharer, partaker, fellowship, partner’; we have been given these promises- not made these promises but they have been fulfilled already:
“For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.”  2 Corinthians 1:20
And by what we now have, he expects us to share in the divine nature, remember the Bible says we are under no obligation to live according to the human nature:
“Consequently, brothers, we are not—with respect to human nature, that is—under an obligation to live according to human nature.”  Romans 8:12, ISV
Because when you got born again, the old man with the old nature died and new man appeared, you don’t have two natures in you but one- the higher nature will always exhibit the characteristics of the lesser nature even better and plus more:
“Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.”  Romans 6:6
It’s important you remember the order, he didn’t say because of the divine nature you can now escape the decay in the world- that would have been nice, but he does even more for you:
“Now unto him that is able to do exceeding abundantly above all that we… think”  Ephesians 3:20
He says you were born decay free with a divine nature; so all you have to do is count it to be so as your reality, affirm and insist!