The Bible tells us that "without faith it is impossible to please [God]" (Heb. 11:6). Any morality, sincerity, or dedication without true God-given faith is no more than dead works. A person can do nothing good or acceptable in God's sight while “dead in trespasses and sins,” “walking according to the course of this world” (Ephs. 1:1-3), in a state of spiritual darkness. His works are defiled, no matter how they appear outwardly and no matter how sincere they are. The main evidence of this state of lostness is unbelief of the Gospel – being ignorant of or not submitted to the righteousness of Christ as the only ground of salvation and as the only thing that entitles anyone to Heaven. All works performed in such a state of unbelief are legal works whereby a sinner, whether he knows it or not, seeks to establish a righteousness of his own (cf. Rom. 10:1-4). This is in direct opposition to the glory of God in salvation based on the righteousness of Christ.
So before there can be any godliness, good works, acceptable obedience, that person must be born again, brought from spiritual darkness to the spiritual light of the gospel. The main evidence of salvation and justification is belief of the Gospel – being submitted to the righteousness of Christ as the only ground of salvation and seeing that His righteousness alone provides me with the whole inheritance of eternal life.
Obedience and good works serve to show our gratitude to God for this great salvation and to prove the genuineness of our claim of salvation. True, God-given faith will be accompanied, to some degree, by good works. But all good works are to be performed with the following attitude – Before I take the first step in a life of obedience, I must see myself as already fully entitled to all of Heaven based on the righteousness of Christ. It also means that as I go about my daily life, I must continually see myself as completely fit and certain for Heaven's glory by virtue of the merits of Christ's righteousness alone. This is what it means to live by faith.