We're not going to go too deep into the seventy weeks revealed to Daniel in chapter 9:24-27, but we should look at why they are important for us and for all of God's children throughout history. This is another prophecy that Daniel can't do anything about but write down. Many have tried to figure out what the prophecy means, and usually one can tell another's theology by how they interpret this passage. Actually, this is a very clear prophecy, once you realize that the things that happen are both causes and effects. The effects described may not happen in the time of the 70 weeks, but the causes do. The chief cause is the incarnation and crucifixion of Jesus Christ, the chief effect is the destruction of Jerusalem in 70AD, about 35 years after the chief cause, and about 30 years outside the timescope of the 70 weeks, but it is an effect. There is nothing wrong with a prophesied effect occurring outside the scope of the prophecy timeline. Christ's crucifixion and resurrection still have effect today, and we live well outside of the phophecy's timeline.
To make the interpretation quick, let's look at the passage. Everyone pretty much agrees that 70 weeks means 70x7 years, so we have about 490 years to play with. All of the things described at the end of the 70 weeks make the most sense about the coming of Christ. Christ puts an end to sin; he atones for iniquity; he brings in an everlasting righteousness. Indeed, he is the most anointed one, the messiah, the Christ. If we count backward 490 years from Christ's crucifixion, we get to the sending of Ezra to Jerusalem in 458. Why Ezra? Why not the decree of Cyrus in 539? Well, Ezra finds the people had again fallen into sin, and he is the one who gets true repentance and covenant faithfulness out of the people, so this is where the "rebuilding" actually begins.
There are also some effects we see in the Daniel 9:24 list: "to finish the transgression" and "to seal both vision and prophet." These two things don't happen with the crucifixion but are big effects from it. The Jews who reject Christ are eventually conquered in 70AD by Titus. This is the finish of the transgression. Finally, the New Testament is written, and the NT is definitely a sealing of both vision and prophet. Nothing new needs to be added to scripture. It is sufficient for all time.
The rest of the passage contains images of both causes and effects. It took about 49 years to rebuild Jerusalem. Christ is the anointed one, the prince of peace. Jerusalem was built in a troubled time. The whole period between Jerusalem restored and Christ coming is a troubled time, with Alexander, Antiochus IV, and Rome hitting the area hard. At the end of the time, Jesus is "cut off," which is legalese for "executed." Titus comes in 70AD and destroys both city and sanctuary. The temple is desecrated before it is torn down, brick by brick, to get the gold plating in the cracks. Jesus made a strong, unbreakable new covenant with his elect. His death on the cross put an end to the sacrifices and offerings of the old covenant. Finally, the desolator is eventually destroyed. God raises up nations to conquer other nations, and these sinful nations are eventually destroyed themselves. If we think of Rome being overrun by the Barbarians, then this indeed is a far-reaching effect of the prophecy.
Ok, we're done with the interpretation. Now, what can we learn from this? First, going back to verse 20, we see that Daniel has been praying, and as he is speaking and praying, confessing his sin and the sin of his people Israel, God sends Gabriel with the prophecy. The archangel says, "At the beginning of your pleas for mercy a word went out, and I have come to tell it to you, for you are greatly loved." Indeed, God has ALREADY given us his word in response to our prayers. Remember, God talks to us through the Bible. How many times are we praying and feeling that we are not receiving an answer to our prayers, when God actually has already responded to our prayers in his scriptures? If we can't find our answer in his Holy Word, then we have been asking for the wrong things, not praying within his will. Everything we need to pray for and everything we need to know in response to our prayer is in the Bible.
Second, the chief cause in the prophecy is our only comfort. Jesus Christ and him crucified is the ultimate cause of all our peace, all our joys. He reverses our spiritual decays, he gives us strength and perseverance. He gives us assurance of our salvation. The search for the answer is not difficult. You can flip to any passage in the Bible and find it. Jesus Christ and him crucified is what the Bible is all about, from cover to cover. When we discover it, peace and joy will reign in our souls, no matter what trials and tribulations happen to our bodies.
Finally, third, the effects of the cause are very real and far reaching. Like the Jews who rejected Christ at the time of his coming, anyone who rejects Jesus Christ is doomed to the same fate. 70AD is going to occur again, and this time it won't be the locals but all the world who will be affected. That is why we are to share the gospel in any way we can with everyone we know. God tells us that when they stand before his judgment seat, they will have no excuse for why they rejected his anointed. Jesus Christ is a free gift for everyone. No one is excluded. Everyone is given, by God's free grace, the gift of Jesus Christ. But many will reject him. Many do not have faith, and it is faith alone that grasps hold of our Lord and Savior. Weep for the lost and pray for their salvation, for the time of judgment is near.