It seems to me that Tim Tebow and Colin Kaepernick represent the two very different forms that American Christianity has come to.
And not just in the United States. In many parts of the world it feels as though the church is separating into two versions, one that values personal piety, gentleness, respect for cultural mores, and an emphasis on moral issues like abortion and homosexuality, and another that values social justice, community development, racial reconciliation, and political activism.
One version is kneeling in private prayer. The other is kneeling in public protest.
One is concerned with private sins like abortion. The other is concerned with public sins like racial discrimination.
One preaches a gospel of personal salvation. The other preaches a gospel of political and social transformation.