Matter is absolutely clear from that Scriptures. Yet it is a wonder of all wonders that JWs got away with their false definition who Christ's brother really is.
Luke 8:21 made it even simpler: "he answered them, “My mother and my brothers are those who hear the word of God and do it.”
Similarly, they got wrongly the definition of pagan. According to God's word a pagan is one who is loving/greeting only those loving/greeting him, ruled by such things as fear, sensuality, ego, greed, alcohol etc (Matthew 5:43–48; Matthew 6:32; 1 Thessalonians 4:5; Galatians 5:19–21; Luke 22:25). (EPH.4.17-19.NIV) (1PE.4.3-4.NIV). This is in the same vein as God's word describes God’s people as “peace-makers, those pure in heart and those circumcised in heart.” (5:9; Psalm 73:1; Romans 2:11, 28, 29; Jeremiah 4:4) Jesus simply praised non-Jews when they displayed theocratic spirit (Mathew 8:10-12; Mathew 22:1-14) and promised he would disown anyone already belonging to him but fails to be theocratic. (Mathew 7:21-23)