If obedience was not necessary then why would repentance be a requirement? Why would God tell us to turn away from sin and then tell us we do not have to then live a life free from sin. We repent from all sin, so we are to live apart from all sin.
Saved from sin to live in sin? I think NOT.
Eph 2:8For by grace are ye saved through faith; and that not of yourselves: [it is] the gift of God:
Salvation from our past sin is from faith and as has already been quoted our efforts to be free from sin is as filthy rags, also
Jer 17:9The heart [is] deceitful above all [things], and desperately wicked: who can know it?
We don't have any strength to obey and yet there are many verses that say to love God is to obey him. Here's one
Jhn 14:15If ye love me, keep my commandments.
How can we obey? When we are saved (Justification) our sins are removed by grace through faith, this is impossible for us to do and is a gift. The same thing happens in our walk (sanctification) we live in obedience and that is also a gift through faith.
Jam 2:20But wilt thou know, O vain man, that faith without works is dead?
Jhn 15:4Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me.
Jhn 15:5I am the vine, ye [are] the branches: He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing.
The fruits come from the vine, but there must be fruit or else
Jhn 15:2Every branch in me that beareth not fruit he taketh away:
Salvation is necessary and is accomplished only through faith.
True works and obedience are necessary and are accomplished only through faith.