If you're willing to listen, you will understand

He that has an ear, let him hear what the Spirit says unto the churches; To him that overcomes will I give to eat of the tree of life, which is in the midst of the paradise of God. Rev 2:7 KJ2000 

The statement is a model of compactness and impact.  It carries with it a punch line from the earliest moments in Scripture.

 
He who

The implication is clear:  if you're willing to listen, you will understand.  This—despite its reputation—is not wreathed in smoke and mirrors;  this statement is plain.

 
Spirit says

This is not John's message, but the Spirit's.  The Spirit is to convict the world of sin, and judgment to come, but this message brings hope of escape from the consequences of sin.

 
To the churches

The noun is plural;  it is addressed to us as well as to the Ephesians.  The message applies for all the church.  Is this surprising, since the Spirit is one source of our unity—One Spirit?

 
Overcomes

The rewards come to the one who overcomes the world, as Christ has overcome the world.

 
The tree of life

Perhaps it seems strange to talk of this.  It is mentioned in the Genesis account of Adam and Eve, and then seldom heard of.  You will recall that an angel was posted to keep Adam and Eve from eating of it—for it gives eternal life.  If they had been allowed to eat of it, sin would have been made eternal, and God can have no contact with sin.  Here we learn that this tree—whatever it is, we can but speculate—is in Paradise with God.

If the literal understanding of this is beyond us, the symbolic understanding is not.  It is very simple:  Adam and Eve were kept from this tree because they were sinners.  Those who overcome will be permitted this tree—which means they are no longer accounted as sinners.  How could that be?  Only through the sacrifice on the Cross.  Only because atonement has been made for our sins by Jesus Christ. 

But there is a restriction:  those who overcome.  In this world we will have trouble, but take heart:  He has overcome the world.  By his grace, through living faith, so shall we.