Does genuine salvation produce a change in lifestyle?
Yes. When there is a genuine salvation, there is going to be a change in lifestyle. Abraham believed God and was declared righteous before leaving Ur, showing salvation is by faith apart from works; yet a changed life follows as evidence, not as the means of salvation.
Les explains that while salvation is by faith alone, many things follow the salvation experience. He says he will not claim to have led someone to the Lord until he sees that changed life; when there is genuine salvation, there will be a change in lifestyle. He illustrates this with Abraham, who believed God and was declared righteous before he ever left Ur. Abraham's leaving was not the works that saved him; he was already a believer before he got out of town. Thus a changed life follows salvation as evidence, not as its cause.