Mark 3 continues the theme of Mark 2. The theme is confrontation.
The religious leaders are not happy with Jesus Christ. In their opinion, he is a blasphemer, a religious rule-breaker, a friend of social outcasts, and a public figure who does not respect their traditions.
They oppose him. They confont him. In fact, in Mark 3 the religious and political establishment meet together (in the back of the synagogue or on a dirt alley behind it) to plot his death.
Christ is also opposed by the forces of hell. Demons in Galilee identify Jesus Christ as the Son of God and openly announce his identity so he will leave them alone.
Further, Jesus Christ is confronted by his own family. They think the crowds and the turmoil caused by his ministry are just too much. Mark writes, "They went out to seize him, for they were saying, 'He is out of his mind.'"
Confronted by the religious and political leaders, demons, his family, and the pressing crowds, Jesus Christ is faithful to his ministry and appoints twelve men to follow him.
Actually, the text says that Jesus Christ "created" the twelve apostles. He created them as the foundation of his church. These men form the foundation of the church of Jesus Christ.
They will spend time with him: talking with him, listening to him, learning from him.
Then they will be sent out from him. They will be sent out to declare the Gospel along the hills of Galilee and in the streets of Jerusalem.
In the midst of confrontation and crowds, Jesus Christ creates. He creates his apostles. He creates the foundation of his church.
Jesus Christ was faithful to his redemptive work. He was faithful to his ministry. Because of his faithfulness, you can trust him. He was not deterred from his redemptive purpose and he finished his work when he laid down his life as a sacrifice for your sins.
His faithfulness means your future is secure. Your future does not depend on what you can merit from God, but rather on the faithfulness of Christ to merit for you what you cannot earn.
That is good news. That is the Gosepl of Jesus Christ.