Romans 1

Romans 1
17.... For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.

And so, Romans is about justification.

More From Romans 1
29 Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers,
30 Backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents,
31 Without understanding, covenantbreakers, without natural affection, implacable, unmerciful:

And, it's also about sin.

But, in the end, Christian life is just the practical matter of living simply, humbly and righteously. And Paul wants to help.

And Finally From Romans 1
11 For I long to see you, that I may impart unto you some spiritual gift, to the end ye may be established;
12 That is, that I may be comforted together with you by the mutual faith both of you and me.