Our salvation comes by faith in Christ alone, but the validating mark of the believer is a life of increasing obedience to the word of God. It is not enough to merely listen to the teachings of Christ. We must obey His Word as revealed in Scripture confessing our sins when needed. Jesus said that His redeemed, eternal family members are those who listen to and obey His teachings.
Then he went home, and the crowd gathered again, so that they could not even eat. And when his family heard it, they went out to seize him, for they were saying, “He is out of his mind.”Mark 3:20-21 (ESV)
And his mother and his brothers came, and standing outside they sent to him and called him. And a crowd was sitting around him, and they said to him, “Your mother and your brothers are outside, seeking you.” And he answered them, “Who are my mother and my brothers?” And looking about at those who sat around him, he said, “Here are my mother and my brothers! For whoever does the will of God, he is my brother and sister and mother.”Mark 3:31-35 (ESV)