Just because Paul SUMMARIZED the Gospel does not mean that you can -- or should -- also summarize it. If you do not preach the full and true Gospel, then you have failed to do your job.
I am in favor of complete presentations of the Gospel. But if someone leaves out the burial or details of the atonement--I see those issues missing in certain presentations of the gospel.
Peter told the crowd in Acts 2 about their killing the Prince of life on a tree. He did not mention the atonement... or not in the text in Acts 2. He could have said it without it being included. I do not see all sermons like this as exact quotes, but as inspired summaries, and if they were spoken word for word, the speakers could also have said other things as well.
I want to be holistic. I want people to hear the full message. But if someone did not hear one detail that one apostle preached...then can I say they are not saved. Often, they repeat prayers and learn more later.
What I really do not like to see are these tag-on altar calls or challenges from the seat where the preacher gives a speech on some modern hobby horse, like how bad the word 'religion' is--using some definition of the term evangelicals probably picked up from some carnal 'spiritual but not religious' folks who hated organized religion in the 1960's, a definition the unbeliever doesn't understand-- followed by an unexplained comment on how important relationship is.
Then it may be followed by a vague unexplained prayer about accepting Jesus into their life. Sometimes they might repeat a confession that they are a sinner. Sometimes they might repeat something about Jesus dying on the cross. It seems like the resurrection is usually missing from either the sermon, the mini-tag on altar call/challenge, and missing from the prayer also. I grew up around prayers that focused on Lordship and the resurrection.
It seems like evangelical, some of whom might turn up their noses at the religious ritual of repeating the apostle's creed in church, have come to treat this repeating-a-prayer ritual as if it were holy. The sinner's prayer ritual is probably 70 years old, and he preached Christ dying for our sins and His resurrection. The prayer used to include confessing one was a sinner, faith in Christ's death for our sins, and the resurrection. The thing is, the apostle's creed is codified and stays pretty much the same. But the Gospel content fell out of the "sinner's prayer" over time in most cases I've seen it in recent decades. And if someone really understands and repeats the Apostle's Creed in faith (we can put 'whole' or 'universal' in there for Catholic maybe), he's going to get a lot more Gospel than some of these 'repeat-after-me-things.
Someone who has a video on YouTube said that this practice is 'easy repeatism.' It isn't easy-believism, because the preacher is not telling the sinner much of anything to believe in them. The way the practice works, it seems the belief is sinner's are saved by repeating a prayer after the preacher, no matter how little is said.
Maybe some of them think any prayer with the name of Jesus in it is calling on the Lord. But I suspect this is what some call a 'monkey-see monkey-doo' type phenomenon, where the preacher has seen it done that way for decades, and does the same thing. And if you asked him, he might say that you have to believe Jesus died for your sins and rose again to be saved. But when it comes to altar call time, they go from rote memory and do what they've seen. Or else maybe they just sort of assume without thinking about it that their audience grew up in Sunday school or just knows all this stuff without them having to preach it.
Do me, it doesn't make sense to not think carefully about what you are preaching. I understand people can misspeak, mispronounce, lose their train of thought. But this sure seems like a big systemic problem, not a little one-off mistake.
Adding all this other stuff to the Gospel and treating it as sacred orthodoxy, like adding 'personal' to 'Savior'-- usually with no explanation for the cheesy-sounding extra verbage, and then religion versus relationship speech, using their own definition of 'relationship' that most unbelievers have never heard makes it harder to communicate. These evangelical cliches become traditions that are treated holy like scripture by many church people.
I have not done a lot of face-to-face evangelistic preaching in a church setting. I did sort of follow the cultural rules the last time I did so. I had them do a profession of faith in a prayer as I recall, after explaining the cross, the resurrection, the Sonship of Christ, that He is Lord. I did not declare them saved. I told them to be baptized. I also do not think I should assume that someone who comes up front, stands up, squeezes a neighbors hand does or does not believe that God raised Jesus from the dead. Giving some people who go through the ritual of confessing some space to hear the word and come to faith if they haven't already may be helpful. If they hear, understand, repent and believe the gospel, then they should be baptized.
I also think it is important to focus on the 'according to the scriptures' aspect, even with Gentiles. Here of late, I've been focusing on Abraham being God's portion, Christ fulfilling God's promise to Abraham, God promising the nations to the Gentile, Jesus being given all authority on heaven and earth, that Jesus is Lord, and the obligation of the listener to recognize that Jesus is Lord and that Christ has authority over all nations including the hearer. God let Gentiles worship idols and go after other religions in times past, but Christ is risen and has all authority, and God is calling all men to repent. The sinner has sinned against God. The sinner who does not believe the Gospel sins with his unbelief.