What is your version of preterism? If that is not too big a question to ask.
I know this isn't directed at me, and I know Parousia70 will do a great job explaining, but here is my take on partial preterism:
1.) THE LAW: was a shadow of Christ. It was not the reality, but only pointed to Jesus and the true reality under Him in the New covenant.
Hebrews 10:1
For the law is only a shadow of the good things to come, not the realities themselves.
Colossians 2:16-17 Therefore let no one judge you by what you eat or drink, or with regard to a feast, a New Moon, or a Sabbath.
These are a shadow of the things to come, but the body that casts it belongs to Christ.
Galatians 3:24
So the law became our guardian to lead us to Christ, that we might be justified by faith
2.) THE PROPHETS: were given messages from God in the form of vision/dreams/riddles/parables, and NOT in clear language like with Moses. These visions, dreams, parables, and riddles, of the Old testament often spoke of hope and vengeance.
Numbers 12:6-7 And he said, “Hear my words:
If there is a prophet among you, I the Lord make myself known to him in a vision; I speak with him in a dream.
Not so with my servant Moses. He is faithful in all my house. With him I speak mouth to mouth, clearly, and not in riddles, and he beholds the form of the Lord. Why then were you not afraid to speak against my servant Moses?”
Hosea 12:10 I spoke to the prophets;
it was I who multiplied visions, and through the prophets gave parables.
3.) The Law, Psalms and Prophets, in regards to hope, spoke of the Cross and the New covenant under Jesus Christ = The kingdom of God.
Luke 24:44. Jesus said to them, “These are the words I spoke to you while I was still with you:
Everything must be fulfilled that is written about Me in the Law of Moses, the Prophets, and the Psalms.”
Acts 3:24 Indeed, all the prophets from Samuel on, as many as have spoken,
have proclaimed these days.
4.) The Law, psalms, Prophets, in regards to vengeance, spoke of the destruction of the 1st century of Jerusalem.
Luke 21:20-22
But when you see Jerusalem surrounded by armies, then know that its desolation has come near. Then let those who are in Judea flee to the mountains, and let those who are inside the city depart, and let not those who are out in the country enter it,
for these are days of vengeance, to fulfill all that is written.
The destruction of 1st century Jerusalem fulfills the great tribulation
Matthew 24:21
For then there will be great tribulation, such as has not been from the beginning of the world until now, no, and never will be.
The destruction of 1st century Jerusalem is therefore referred to as "Jesus coming in judgment upon Israel". Jesus states the vineyard owner was to come and destroy the wicked tenants who murdered the servants and son of the vineyard owner.
Matthew 22:40-41
When therefore the owner of the vineyard COMES, what will he do to those tenants?” They said to him, “He will put those wretches to a miserable death and let out the vineyard to other tenants who will give him the fruits in their seasons.”
This type of Judgment was common in the old testament:
a.) God coming down from heaven to judge David's enemies
2 Samuel 22:10 He bowed the heavens and came down;thick darkness was under his feet.
b.) God coming down from heaven to judge Egypt
Isaiah 19:1 An oracle concerning Egypt. Behold, the Lord is riding on a swift cloud and comes to Egypt;
c.) God coming down from heaven to judge samaria
Micah 1:3 or behold, the Lord is coming out of his place,and will come down and tread upon the high places of the earth.
Thus, the overwhelming majority of OT scripture finds its fulfillment in Christ at His first coming (ministry, death, resurrection, ascension, sending of the Spirit, reign, and spread of the gospel), and secondly in the destruction of 1st century Jerusalem (the great tribulation, days of vengeance, coming of the vineyard owner).
However, under the partial preterist belief system, this does not preclude the fulfilment of a future coming of Christ, a future judgment of the righteous and unrighteous, or a future resurrection of the righteous and unrighteous.