How would you share a Reformed understanding of the gospel with a nominal or modern American evangelical Christian?
What makes a Reformed understanding of the gospel is the desire and the passion that God the Father, God the Holy Spirit, and God the Son receive the fullest measure of the glory they should receive in saving me.
God will not get the fullest glory that he should have as the Father unless we come to terms with the fact that he chose me apart from anything in myself. The glory of the Father's grace in choosing me will not shine as brightly as it ought to until we realize that I was chosen before I was born or had done anything good or evil, according to Romans 9:11.
The Holy Spirit will not get the fullness of his glory if we do not say to him, "We know that by your power alone I was so conquered in my dead, rebellious heart that Christ was made to appear irresistibly beautiful. It was by your work alone and by nothing in me!"
Nothing in me contributed to the fact that Jesus became irresistibly beautiful to me. That's all the work of the Holy Spirit illumining my mind, stripping away the blindness, and giving me eyes to see. So let the Holy Spirit have the fullness of his glory for my seeing Christ as compelling so that I freely fly to him for forgiveness.
And Jesus Christ will not get his glory if we do not realize that on the cross he bore my sin in such a way that he secured that privilege that the Holy Spirit worked in my heart.
So the point to stress in sharing the gospel is, "I want you to hear the best news in all the world, namely that Christ died for your sins such that if you will believe on him you will be saved. And the way that God gets all the glory in that is for you to realize that he chose you, the Holy Spirit decisively overcomes your deadness, and Christ really did cover all of your sins such that he secured for you even the faith that you are now about to exercise. Would you not believe in this glorious Christ?"