Rom 4:2 For if Abraham was justified by works, he has something to boast about, but not before God.
Rom 4:3 For what does the Scripture say? “Abraham believed God, and it was counted to him as righteousness.”
Rom 4:4 Now to the one who works, his wages are not counted as a gift but as his due.
Rom 4:5 And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness,
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Here in v.4 works and belief are separated and clearly defines belief as not a work. Neither does it define belief as a gift.