Given that the law of Moses was nullified when Christ died on the cross, and that there is no scriptural reference to the gospel being preached prior to the day of Pentecost (assuming these two statements are correct):
For illustrative purposes, let’s say there was a Jewish child in a covenant relationship with God prior to the death of Jesus, who, before the day of Pentecost becomes of the age of accountability, sins, and immediately dies never having been exposed to the gospel. Assuming my concepts above are correct, what would be the spiritual state of this now young adult?
This is an interesting question; however, it is not one that is relevant to any person now living. There is a related question that applies to the Gentiles since the gospel was not proclaimed to them until Acts 10.
First, the Jews. The work of John the Baptizer was a transitional period as he prepared the way of the Lord. His work was, among other things, to make ready a people prepared for the Lord. Luke 1:17. This he accomplished through his preaching and baptizing converts for the remission of sins. During this period the Law of Moses was the applicable rule of religion and government for the Jews. As a rule of government it continued until the destruction of Jerusalem in 70 A.D. When did the New Covenant become effective for the Jews. The Book of Hebrews perhaps gives some insight. “16 For where a testament is, there must also of necessity be the death of the testator. For a testament is of force after men are dead: otherwise it is of no strength at all while the testator liveth.” A testament or will becomes effective after the death of the testator. Even with the wills of men that is true, but to become effective a will must be probated. Under the New Testament of Christ, it was not proclaimed, or one might say probated, until the day of Pentecost. At that point the Jews were subject to its commands and, upon obedience, would receive its promises. That this is correct is supported by the fact that Jesus promised a new Comforter, the Holy Spirit, who would come with power with the coming of the Kingdom. Mark 9:1. That power came on the day of Pentecost in fulfillment of Joel’s prophecy. Until that time there was no kingdom into which the young Jew whom you postulate could have be translated. After that day, it was possible. Colossians 1:13.
The religious rules for the Gentiles until Acts 10 continued to be the patriarchal law under which they had always been. The gospel spread as the Lord had commanded, first to Jerusalem, then Judea, then Samaria, and then to the uttermost parts of the earth. Luke 24:47; Acts 1:8.
Since the gospel has now gone to all, all are subject to it. Thus, it is not possible for the conditions that prevailed for the first Jewish converts and the first Gentile converts can never be repeated. The question relates only to academic curiosity. It has no application to any person in this day.
You Must Hear the Gospel
You must hear the gospel and then understand and recognize that you are lost without Jesus Christ no matter who you are and no matter what your background is. The Bible tells us that “all have sinned, and come short of the glory of God.” (Romans 3:23) Before you can be saved, you must understand that you are lost and that the only way to be saved is by obedience to the gospel of Jesus Christ. (2 Thessalonians 1:8) Jesus said, “I am the way, the truth, and the life: no man cometh unto the Father, but by me.” (John 14:6) “Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved.” (Acts 4:12) "So then faith cometh by hearing, and hearing by the word of God." (Romans 10:17)
You Must Believe
You must believe and have faith in God because “without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.” (Hebrews 11:6) But neither belief alone nor faith alone is sufficient to save. (James 2:19; James 2:24; Matthew 7:21)
You Must Repent
You must repent of your sins. (Acts 3:19) But repentance alone is not enough. The so-called “Sinner’s Prayer” that you hear so much about today from denominational preachers does not appear anywhere in the Bible. Indeed, nowhere in the Bible was anyone ever told to pray the “Sinner’s Prayer” to be saved. By contrast, there are numerous examples showing that prayer alone does not save. Saul, for example, prayed following his meeting with Jesus on the road to Damascus (Acts 9:11), but Saul was still in his sins when Ananias met him three days later (Acts 22:16). Cornelius prayed to God always, and yet there was something else he needed to do to be saved (Acts 10:2, 6, 33, 48). If prayer alone did not save Saul or Cornelius, prayer alone will not save you. You must obey the gospel. (2 Thess. 1:8)
You Must Confess
You must confess that Jesus Christ is the Son of God. (Romans 10:9-10) Note that you do NOT need to make Jesus “Lord of your life.” Why? Because Jesus is already Lord of your life whether or not you have obeyed his gospel. Indeed, we obey him, not to make him Lord, but because he already is Lord. (Acts 2:36) Also, no one in the Bible was ever told to just “accept Jesus as your personal savior.” We must confess that Jesus is the Son of God, but, as with faith and repentance, confession alone does not save. (Matthew 7:21)
You Must Be Baptized
Having believed, repented, and confessed that Jesus is the Son of God, you must be baptized for the remission of your sins. (Acts 2:38) It is at this point (and not before) that your sins are forgiven. (Acts 22:16) It is impossible to proclaim the gospel of Jesus Christ without teaching the absolute necessity of baptism for salvation. (Acts 8:35-36; Romans 6:3-4; 1 Peter 3:21) Anyone who responds to the question in Acts 2:37 with an answer that contradicts Acts 2:38 is NOT proclaiming the gospel of Jesus Christ!
You Must Be Faithful Unto Death
Once you are saved, God adds you to his church and writes your name in the Book of Life. (Acts 2:47; Philippians 4:3) To continue in God’s grace, you must continue to serve God faithfully until death. Unless they remain faithful, those who are in God’s grace will fall from grace, and those whose names are in the Book of Life will have their names blotted out of that book. (Revelation 2:10; Revelation 3:5; Galatians 5:4)