Our salvation is all of grace, but that doesn't mean loitering till grace comes. God gives us plenty to do, and while these things are not for earning grace they are for accessing it.
God gives us rules to live by and that's a good thing. We can choose to walk in the pathways of grace, and therefore in the way of blessedness:
"Blessed are those whose way is blameless, who walk in the law of the LORD … who also do no wrong but walk in his ways!" (Psalm 119:1-3)
God actually wants us to seek to please Him:
"… try to discern what is pleasing to the Lord" (Ephesians 5:10).
He goes so far as to say that keeping His commandments is what "counts":
"For neither circumcision counts for anything nor uncircumcision, but keeping the commandments of God" (1 Corinthians 7:19).
This is not a contradiction of the doctrine of faith but an elaboration on it: True faith means believing God enough to do things His way.
And so God kindly eliminates the guesswork about how to please Him. He tells us things like: "Give thanks" (Ephesians 5:4), "walk worthy" (Ephesians 4:1), "cleanse ourselves from every defilement" (2 Corinthians 7:1), "imitate" the people who are doing it (1 Corinthians 4:16; 11:1), "entertain strangers" (Hebrews 13:2), "do everything without complaining or arguing" (Philippians 2:14)-and many other directions.
I like to know where I stand. I like to know that although my salvation is the sovereign gift of God, He gives me ways to enjoy it and to be sure that I am experiencing it to the max. Who wants to constantly land in the ditch when you can walk between the guardrails of the pathways of grace?