Oh, we don't come right out and say that. We don't have to, our lives say more than our words. The truth is that we can't live by faith devoid of His Word and we'll never be learners and doers of His Word until we get over this sinful notion of self-sufficiency. Jesus said that man couldn't be sustained by bread alone. If we were nothing more than animals' bread would be enough.
Instinct drives the beast.
The senses serve the animal kingdom well but the inhabitants of the kingdom of God need more. The trinity of Man, spirit, soul and body, requires heavenly food. So, the Christian that seeks the strength to walk out this journey without stumbling repeatedly will need to partake of the food that fuels faith. Life provides many opportunities that test our faith. It's not that God desires to see what we're made of, but rather, He desires to show us what we're made of.