53 For this perishable must put on the imperishable, and this mortal must put on immortality (1 Corinthians 15:53)

The body we have is perishing. The process of decay begins pretty much immediately after birth. As we get into our latter years we can see and feel the rapid nature of that decay.

Thus, when we die we must put on a body of immortality to reside in heaven where there is no decay. Because the mortal cannot reside with the immortal.

While this is a mystery we will not fully grasp until we get to heaven, we can grasp now the fact that with Christ we are saved. And with this salvation we have already put on the beginnings of immortality.

The beauty of this immortality without decay is that we will not succumb to the fallen nature of our world. We will reside in paradise and the struggles of this world will fall away.