Practically everyone in the western world who even has a passing familiarity with modern Christianity, knows about the now classic four spiritual laws and the so-called 'sinner's prayer,' even the large majority that has not 'tried' it. To review, this sale's pitch says God loves you and has a wonderful plan for your life. But, you are a horrible sinner and God demands payment for this sin. Jesus paid for the sin. Soooo- ask Jesus into your heart and to forgive you and you too can have an iron clad guaranty of an eternity in heaven. If you ask for the rationalization for such a prayer from the Bible, Romans 10:9-10 will be the usual answer.
Romans 10:9-10 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
Romans 10:13 For whosoever shall call upon the name of the Lord shall be saved.
While I don't dispute that one can ask for their salvation, the normal admonition is to believe. So I will assume that you are then generally familiar with salvation's message and in this consideration go on to parse what Romans 10,9-10 could possibly be saying. Please consider that when a man "believes unto righteousness," he specifically believes in the resurrection. Why is this important? Because in a previous part of the letter to Rome,
Please observe that in order to make the journey to Jesus' seat of pardon authority, you must completely pass within the borders of His kingdom with all of your being. To stand in prayer before him to ask forgiveness is to also assume that he will use the power of His cross in your life in whatever way He continues to see fit (including the way it is presented in Romans 6), and He will interfere in your daily affairs in any way that pleases Him from that day forward. Jesus does not run foreign embassies in Satan's domain. If you assume that you can mumble a repeat after me prayer, have God stamp PAID on your rap sheet, and you can return to life as it was - then you have prayed to a dead jesus to no effect, even if the life you imagine you are returning to is that of a self willed religious boy scout.