Early in Christ's ministry he encounters conflict and controversy.
Jesus Christ heals the sick, teaches about the Kingdom of God, casts out demons, and forgives sins. However, instead of celebrating his work, many of the religious leaders oppose him. They are not happy because he seems to disregard the religous rules they have put their faith in as pious leaders.
For example, while the Pharisees carefully fast from food each Monday and Thursday to demonstrate their committment to God, Jesus Christ is found eating and drinking with sinners. He and his disciples do not fast. They feast.
Further, instead of staying home on the Sabbath and refraining from any work like the Pharisees, Jesus Christ's disciples are caught walking through a field grabbing heads of grain to eat. The Pharisees assert that Jesus Christ and his men are breaking the Mosaic law.
Yet, instead of criticizing the disciples for working for food on the Sabbath, perhaps the Pharisees should have fed them. Inviting the disciples over for lunch would have solved the problem, but the Pharisees were not looking for opportunities to demonstrate mercy. They were looking for opportunities to demonstrate their self-righteousness.
The religious leaders were following religious rules and trusting that their obedience would earn them God's favor.
Today, you and I can have that same temptation. The temptation to trust in our spiritual actions to earn God's favor. The tempation to believe that our consistent worship attendance, our tithing, our personal devotional reading, and our attendance at Christian conferences and retreats can somehow help us in the economy of God's Kingdom.
In other words, you and I can act religious and trust that our actions will earn God's pleasure. Religion can be a form of meriting God's mercy rather than receiving it.
The Gospel of Jesus Christ is the good news of what God has already done for you through the life, death, and resurrection of the Son of God. It is good news of what a holy God has done for you - a sinner - because he is gracious towards you.
The Gospel implies that your religious actions - your obedience - cannot merit the mercy and grace of God. Rather, your religious actions should be done in response to God's mercy and grace which was demonstrated through the crucifixion of the Son of God.
What you do today, tomorrow, and the rest of your life will never save you. But, what God has already accomplished through Jesus Christ secures your salvation.
As a result, your obedience should be done in response to God grace, not as an attempt to earn it.