Altar calls are a fairly new creation in Christian history. They are believed to have been started/ created by Charles Finney. He often times used "anxious seats". The reason for these seats were to force a decision, to get results.
There were in fact many decisions made using this method. Many since Finney have evolved the altar call into what it is now - A vain attempt by man to force a decision and avoid the work of the Holy Spirit on a persons conscience and soul. Some of the well known preachers that use or have used this method are D.L. Moody, Billy Sunday, Luis Paloa and Billy Graham.
While scripture does tell us to "Compel them to come" and "I beseech you, be reconciled to God", there is no mention of an altar call, an anxious seat or anything remotely close. Don't get me wrong, I am in favor of altar calls if God's Word has been properly proclaimed and His Spirit has done a work in someone's conscience and heart. With that being said - 5 stanzas of "Just As I Am", "I Surrender All" or "Softly And Tenderly" are probably not great works of God in a mans heart - they are songs that are used to inspire emotion that leads to decisions that lead to numbers.
The most dangerous part of this is the declaration by an altar worker, elder or pastor that someone has "asked Jesus into their heart", "made a decision for Christ" or most commonly "been saved today". With this declaration many people are being sent a firey hell. Salvation is not a walk down an isle, it is not a decision, it is not a temporary feeling that lasts for a little while and then goes away. Salvation is permanent, you can not lose it and once you have it you will walk with God, you will REPENT daily and you will be changed - BORN AGAIN. Many people are under the false impression that since a preacher told them they were saved that they have it all taken care of now. Nothing in the bible is spoken of salvation being a one time thing, salvation is an ongoing, growing existence that is evidenced by a disdain for sin, an open proclamation of Gods work in their life and a markedly changed lifestyle. We are commanded to test and examine ourselves that we are in the faith, not look at the day written in the back of our bible, recall a time walking down the isle, a decision, baptism, or "asking Jesus into your heart".
Let's break down the term "Born Again" because it seems to be thrown around a lot these days, with very little thought on it's meaning. Think of natural/ fleshly birth. If you are born a Caucasian, there is no way you can become Asian, a puppy can not become a kitten, a fish can not become a elephant. When a person becomes Born Again - they are rebirthed with a new heart, they are a new creation in Christ. A truly born again, repenting Christian can then not become a sinner again. It is not in their "make up", it is not possible. They will walk in the light of the Lord and shun the darkness, they will want to please the Lord and when they do fall into sin - they will repent, they will not use the saving grace of Christs death, burial and resurrection as a "get out of hell free card". That is an open disdain and is a lie from the pits of hell. A true Christian will be so heartbroken when they sin, that they are causing their Father pain, that they will cry out for mercy and forgiveness.
What has happend to Christianity in the USA? No where else has a decison taken the place of a true life changing experience with God Almighty. No where in scripture can be found of a decision, a walk down an isle, a magical prayer, being baptized or a proclamation by anyone other than Christ been a sign for being born again. But so many these days are being deceived by the millions. Stand in front of a pub and ask everyone that enters and stumbles out if they are a Christian and at least 75% will declare they "took care of that a long time ago" or that they are saved. Is that the case with you? Have you had a life changing experience with the Lord? If not I beg you with all that I am to repent and turn from your sinful life. Any questions? Feel free to contact me, I will show you the biblical way to salvation, and it won't be the Roman Road or 4 Spiritual Points.
Paul Washer Explains it a lot better than I can.