“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

See how he qualifies the promises we have received- ‘exceeding great’ and ‘precious’. We received them when we got born again, the Bible says:
“Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new.”  2 Corinthians 5:17
So once a man enters Christ, he becomes a new creation; his newness is defined absolutely by his location; when he moves from the kingdom of darkness- the world and its systems- to the kingdom of light- Christ, he becomes a new man; only new (and uncommon) men are found in Christ, but there’s something else about this new location:
“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
All of God’s promises are answered ‘Yes’ and have been given- no conditions attached!
Now he tells us why we have these promises, not just for the fun of it, but to enable us live out fully the divine nature that we have received- in Christ, we are new men with a new divine nature, and so God gives us his word (promises fulfilled) to live out that new nature fully!
In this revelation, he lets us know that living out the new nature goes beyond trying to escape the decay of the world because we already did so when we got into Christ- it is more about walking as Jesus walked with his life and fellowshipping with our heavenly father than it is about escaping lusts.