Obedience to God is the outward expression of the inward reality, faith in Jesus Christ.
Obedience without faith is self-righteousness.
Faith without obedience is self-deception.
Faith and obedience are inseparable, like husband and wife. Not perfect, but complementing each other.
When I speak of our faith in Jesus Christ, I mean it's a justifying faith. Faith that justifies a sinner. Faith which receives "the free gift of righteousness", the perfect righteousness of Jesus credited or given to us, simply through the chanel of faith, or trust.