Most who read this blog already have an understanding of those truths - but even we who are saved are to meditate on and rejoice in the gospel. :)
For that reason, I've started reading (again) The Gospel According to Jesus. I want to have a firm grasp on the message we are called to share. I found the following quotes from MacArthur to be a refreshing reminder of the simple, yet powerful truth of the gospel:
"Sin is no peripheral issue as far as salvation is concerned; it is the issue...the distinctive element of the Christian message is the power of Jesus Christ to forgive and conquer our sin. Of all the realities of the gospel, none is more wonderful than the news that the enslaving grasp of sin has been broken...
The gospel according to Jesus is first of all a mandate for repentance...From the beginning of Jesus' ministry, the heart of His message was a call to repentance. In fact, when our Lord first began to preach, the opening word of His message was "Repent" (Matt. 4:17). It was also the first word of John the Baptist's message (Matt. 3:2) and the basis of the gospel the apostles preached (Acts 3:19; 20:21; 26:20). No one who neglects to call sinners to repentance is preaching the gospel according to Jesus."
Which verses do you (or would you) most often use in communicating the gospel to unbelievers?