I like to think the writer of Hebrews was a sports fan.The analogies he uses would certainly lead one to support this idea. Just as the writer referred to great numbers of witnesses, we athletes often compete in front of an audiences of great numbers.
This is also true in the Christian walk. Both believers and nonbelievers comprise our audience. There are those who encourage us: our pastors or our Sunday School teachers; and then there are those who "boo" us, ones who are opposed to any semblance of commitment to our Lord.