The Republican governor says he rejects complaints that Houston "forfeited the good things that she did" because of her struggles with substance abuse.
"What I would say to everybody is there but for the grace of God go I," he said on Wednesday.
Twitter was abuzz with reaction to Christie's decision. The honor, according to one person, should be reserved for members of the military, first responders and elected officials.
Houston's funeral is Saturday at a Newark church where she sang as a child.
She died in Beverly Hills, Calif., on Saturday at the age of 48.