"Write the gospel in your own words to the best of your current understanding. Share and discuss. Later, return to this answer and compare it with your understanding at the end of the course".
I really thought about it hard for a long time then came up with the following description, which is the best of my current understanding and belief.
God has paid for our debts/sins with the ultimate sacrifice out of His love so that we can be sinless in order to be with Him eternally.
I'm now looking forward to the end of semester to see if my understanding of the gospel will change...