The Work Is To Believe.

 Too many believe their good enough status causes their justification in the sight of God. They consider themselves godly, God-fearing people and as such they are superior to all the ungodly, non-God-fearing people who make no claims to belong to God. Yet the truth of the matter is only the ungodly are justified by God. Yes, you read that right. Everyone has to realize, and have a deep-seated comprehension of the fact they have absolutely NO righteousness of their own at all and none of their claims will give them righteousness. They could be perfect God-fearing people in all their actions but unless they realize their perfection is filthiness, stained by the sin that caused ALL their righteousness to be like filthy rags, it means nothing. God alone justifies the ungodly and our believing that God does this, that Christ is our righteousness will make it so.  Truly the ungodly are justified by God, because we can be nothing but ungodly without God's righteousness. 

We are told…

Joh_6:29  Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.

The work is to BELIEVE on Christ and His righteousness!

(Excerpt)

Romans 4:5 But to him that worketh not, but believeth on Him that justifieth the ungodly,  his faith is counted for righteousness

Justifying the Ungodly. 

God justifies the ungodly. No others need justification. 

But mark that he does not justify ungodliness. 

That would be to call evil good, and to deny himself. But he justifies or makes righteous the ungodly, and that is just what they need. He justifies the believing sinner by making him a new man in Christ Jesus, and this he can do and still be just. To make a new man in righteousness is perfectly in harmony with his own character as Creator.

Working Not. "But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness." 

Bear in mind that justification is the subject under consideration. When the apostle speaks of not working, it is evident that he means not working in order to be justified. A man is not made just by works,  but the just man works yet always by faith. "The just shall live by faith."

Rom_1:17  For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.

 It is faith that makes him continue to live justly. The reality of the works of faith is made more prominent in the latter part of this chapter.