If we look at the history of the Jewish people, is it the same as what the Bible predicted? For example, if the Jewish people no longer existed, we could throw the God of the Bible out as being the true God because God made an everlasting covenant with the Jews. I don't think any cities in the Book of Mormon have been found. I am not as familiar with the Koran as I am with the Bible but I think the Koran predicts mostly blessing for its followers which is in contrast of what the Bible predicts for the Jews.
Deut. 11:26-28 (All Bible quotes King James Version)
Behold, I set before you this day a blessing and a curse;  A blessing, if ye obey the commandments of the Lord your God, which I command you this day:  And a curse, if ye will not obey the commandments of the Lord your God, but turn aside out of the way which I command you this day, to go after other gods, which ye have not known.
Deut. 28:64-67 And the Lord shall scatter thee among all people, from the one end of the earth even unto the other; and there thou shalt serve other gods, which neither thou nor thy fathers have known, even wood and stone.  And among these nations shalt thou find no ease, neither shall the sole of thy foot have rest: but the Lord shall give thee there a trembling heart, and failing of eyes, and sorrow of mind:  And thy life shall hang in doubt before thee; and thou shalt fear day and night, and shalt have none assurance of thy life:  In the morning thou shalt say, Would God it were even! and at even thou shalt say, Would God it were morning! for the fear of thine heart wherewith thou shalt fear, and for the sight of thine eyes which thou shalt see.
This last passage seems to be what happened after the destruction of Jerusalem in 70 A.D. and more recently in Nazi Germany. Why the harsh punnishment? The only logical reason would be that in supermajority part, they continued to deny Jesus Christ as their Messiah.
I believe that God instituted the laws for his people to prepare them for the coming of Jesus Christ. There was a reason God made Abraham put Isaac on the alter. There was also a reason for all the bloodshed of the animals for sin offerings. Isaac was supposed to be Abraham's only son, the son of the promise. Do you see the parallel between Abraham and Isaac, and God the Father and Jesus Christ?
Jesus Christ was the sacrifice for sins once and for all and The Law was the foreshadowing of the Messiah. If the Israelites loved God more and followed His Law, it would seem to reason that the severity of Christ's suffering would have been reduced. There would have also been less fake writings for us to stumble over. I think that while Jesus was on earth, he was the embodiment of Israel. The Jews rejected God for most of their history so they were made to reject Jesus.
Have you ever wondered what would have happened if things were different and Israel tried the best they could to obey God's commandments? I think that the prophets would have been told to write differently and Israel would have been the world superpower. Since Israel was the center of the world at the time (by design I think), their religion would have been dominant and pure.
History shows that it took less than 500 years to get from 1st century living to what we have today. I can argue that America was blessed because from its beginning, although not perfect, the people tried to follow God's plan. Look at some of the founding fathers' writings and you will see that God is mentioned many times. Did we get to where we are today because we were smarter than before or more moral. Maybe we were smarter because we were more moral.
I see no reason for the 1st century world to not have the same things we have if Israel kept God's commandments instead of prostrating the Temple for instance. Maybe the people would have had to give Jesus a few stripes and a lethal injection. Then they could have watched Jesus' resurrection on TV and Jesus would have became the in fact ruler of the world by the people's choice.
Adam and Eve decided they knew better than God. God made a plan of salvation available to everyone. As to the question why did God not write things that were unmistakably His? I think he did but anything can be counterfeited. The question is why do people say they have visions from God when they haven't?