Excellent explanation, especially showing how all of the Bible ties in together. The story of the Prodigal son also ties in with this, as an example of God's (the father in the parable) unconditional love and grace for us, the Prodigal son being truly repentant and receiving God's forgiveness, and the other son, with his unforgiving attitude toward his brother. "I've worked longer and more, I deserve more."
Again, great job of unpacking this parable.