We see Jesus first message or theme. Luke records Jesus reading from from the Old Testament about how God is going bring about salvation and healing and is rejected, while Matthew doesn't record a specific sermon, just the message of His preaching. Repent!
This is consistent with Luke, for the way that God brings about healing and salvation is through repentance. Isn't it interesting that this would be Jesus first message? Repent. While He would preach and live out the message of God's redemptive love, His first message was repent.
Repentance is the beginning step to knowing God. Repentance is not the end of faith, rather is is one of the beginning. Until God calls us with His prevenient grace to repentance as the first step in the journey of knowing Him. We cannot fully understand God's great love for us until we have come to understand just how much we need it. We can't understand the joy of salvation until we have been set free. We can't know that joy of communion with God until we see that our sin separates us.
And that is why we must repent of sin, because it keeps us from God. And no sin is worth being separated from God. No habit, no hobby, no desire, no anything is worth being separated from God. And the only way to over come that separation is to respond to God's grace and repent.
Repentance is not just feeling bad for our sins, that is conviction. Let us not mistake conviction for repentance. Jesus didn't say be convicted, He said, repent. It is not just enough to bad about your sin, what will you do about it? Repentance is a turning from.
And repentance is not just something we do preceding our conversion, it is something we must do each day of lives. We must allow God's grace to search within, find the sin within, and turn from it. Today, Jesus message to us is repent. Today, do you repent of your sins, do you turn from them? Do you turn to your God and live in His salvation? Today, repent, and believe the Gospel.