Even though we see in Scripture that it is God who keeps a believer to the very end, there's another stream in the Bible that makes it clear that the Christian must also persevere to the end. God will give the strength, and He guarantees the victory, but the Christian must conquer.
We see this in our verse today:
He who has an ear, let him hear what the Spirit says to the churches. To the one who conquers I will grant to eat of the tree of life, which is in the paradise of God. (Revelation 2:7)
Part of salvation is that God has given us ears to hear. And for we who have ears to hear, Jesus calls us to hear "what the Spirit says to the churches." Now, this is tagged on to the letter to the Ephesians, but certainly, it's a call for every Christian. Pay attention to what Christ has said to them. Pay attention to what He's about to say to the rest of the churches.
It's notable here that Christ calls them to hear "what the Spirit says to the churches." Christ is delivering the message, but it's the Holy Spirit that helps the Christian hear. Christ's message is the Father's message is the Holy Spirit's message. They don't tell us different things. They are three persons but one God.
Right next to this exhortation to hear what God through Christ and the Holy Spirit is saying is a promise: "To the one who conquers I will grant to eat of the tree of life, which is in the paradise of God." What we can infer from this juxtaposition is that if you hear what the Spirit says, you're going to conquer. There is an inseparable connection between hearing God and making it to the very end.
To conquer, here, means to overcome the trials of this world. They are many. But we take heart because Christ has overcome the world already (John 16:33), and through His Spirit, He will help us do the same thing. And one of the means that He uses in order to help us persevere to the very end is His very word.
If you listen to Him, then by the help of the Holy Spirit and the strength of Christ, you will conquer. And if you conquer, God will grant you to eat of the tree of life, which is in God's paradise.
Do you remember why Adam and Eve were removed from having access to the tree of life? Genesis 3:22 says, "Behold, the man has become like one of us in knowing good and evil. Now, lest he reach out his hand and take also of the tree of life and eat, and live forever..." If they had eaten of the tree, they would've lived forever. Of course, they would've lived forever in their sinful state, so that wouldn't have been good. But if and when we conquer, by His grace, He will allow us to eat of that tree and live forever, this time having been justified by Christ and having been given imperishable bodies.
So, conquer, saint. By the power of the Holy Spirit and with the promise of God that He will not let you go, run hard to the very end. Listen to what the Spirit has revealed to the churches through His word. And you will live forever with Him.
My friend, the unbeliever, this is only available to those who trust in Jesus Christ, who died on the cross for sinners like you and me. Put your faith in Him and join us with Him for eternity.