Mark 3:20-35
Always ready to let people come near to Him, the Lord allows the crowd to fill the house which He had entered. He immediately starts to teach them without even having time to eat. We who often are so little disposed to open our doors to strangers, to let ourselves be disturbed or to change any of our habits, let us follow this example of tireless devotion and complete self-denial. Let us also remember that even an undesirable visitor may be sent to us so that we can speak to him about the salvation of his soul.
Some people are troubled about the meaning of v. 29. They fear that they may once have spoken, by accident, a sinful word which could never be forgiven. This is to misunderstand the grace of God. "The blood of Jesus Christ his Son cleanseth us from all sin" (1 John 1:7). Blasphemy against the Holy Ghost was the terrible sin of unbelieving Israel. These people attributed to Satan the power of the Holy Spirit who was in the Lord Jesus. It was extremely serious and the absolute opposite of common sense (v. 26).
In the last paragraph the Lord marks out clearly those whom He considers to be members of His family. To do the will of God was, and still is, to listen to the Lord Jesus.