Again, if one is saved by faith alone in Christ alone then there's no requirement for works afterwards either, in fact, even a man with no evidence is still saved if he trusted Christ.
Clearly, redundantly, WORKS will gain no one salvation. But the other key truth is, just because one is saved, WE can't always determine whether there in fact are works - ones we would recognize as confirmation of someone's faith. Again, such evidence can also be manifest by those who do not have more than intellectual belief. Especially in a new Christian, we may not see the kinds of confirmation of faith we might expect. So, was their "simple prayer" effective or not? Maybe. Even very likely. But it depends upon their heart and mind toward Christ - which knowledge of, by men, may be nonexistent.
I believe that no saved person will be without some works AFTER salvation, but that this does not mean any one man can necessarily discern them. So if the issue is that we can't always KNOW whether a person is saved or not by our individual fruit searches, then we just need to relax and leave that to the only One Whom CAN discern and intimately knows minds and hearts and even the smallest of what HE considers works.
Here's some LS-type quotes attributed to Paul Washer. Though some statements concern me, much of what he otherwise preaches I can accept:
“the proof or validation of genuine conversion is that the one who professes faith in Christ perseveres in that faith and grows in sanctification throughout the full course of his life. If a person professes faith in Christ and yet falls away or makes no progress in godliness, it does not mean that he has lost his salvation. It reveals that he was never truly converted.”
""If Jesus Christ isn't strong enough to motivate you to live biblically, you don't know Him at all."
""If you are going to walk with Jesus Christ, you are going to be opposed by everything in the world and by the great majority of evangelicals. You're going to be opposed."
"Most people today in our churches are lost, and they demonstrate that they are lost because their entire Christianity is nothing more than, 'They made a decision.'"
"The truth is this: I am a Southern Baptist, and the great majority of Southern Baptists are lost."
"If you have made the good profession, if you claimed to have passed through the gate, if you have received baptism in a public declaration of your faith, and you begin to walk-it doesn't matter how long it appears you're walking in that path-if you step off that path and there's no discipline and you continue on that path, you can have no assurance whatsoever of your salvation. And it is not that you lost your salvation, it's that you're showing now that you never had it. If we would only preach these truths..."
"When you refuse to teach on the radical depravity of men, it is an impossibility that you bring glory to God, His Christ, and His cross, because the cross of Jesus Christ and the glory thereof is most magnified when it's placed in front of the backdrop of our depravity!"
"We have taken the glorious gospel of our blessed God and reduced it down to four spiritual laws and five things God wants you to know, with a little superstitious prayer at the end; and if someone repeats it after us with enough sincerity, we popishly declare them to be born again. We've traded regeneration for decisionism."
"The man who desires to receive the benefits of the gospel must first decide if he is willing to turn over all autonomy and self-government to the Lord of the gospel."
"There are many who believe they are saved and thoroughly Christian because they once prayed a prayer and asked Jesus to come into their hearts. However, they did not continue on in the faith. They never came out of the world, or if they did, they quickly returned. They possess no practical reality of the fear of the Lord. There is no fragrance of divine grace in their lives. They show no outward evidence of inward transformation. There is not even a hint of the divine discipline that God provides to all His children. Yet they stand assured of their salvation because of one decision in their past and their belief that their prayer was truly sincere. No matter how popular such a belief may be, it has no biblical grounds."
"The evidence of a genuine saving work of God in the past is the continuation of that work into the present and until that final day. We are saved if we hold fast to the word that was preached to us [1 Cor. 15:2]. We can have little or no assurance of salvation if such is not the case."
"In the gospel of Jesus, sincere and costly discipleship always accompanies genuine conversion. ... The gospel of Jesus teaches men that a mere profession of faith alone is no sound evidence of salvation."