(this is longer than the typical GLC blog, but I think is a needed reminder for us. . . Tim Keller and John Piper deserve credit for some of the arguments here.)
As people interact with the Bible today, one critique that often gets thrown at Christians is that we pick and choose which portions of the Bible to believe. "Look at the Old Testament laws", we hear, "Are you still against eating Pork, what about Shellfish! Do you wear a shirt with mixed fabric! What's your view on the cooking of goats!" (obscure, that last one)
The argument goes. . . "How could you be against gay marriage, fornication, or the death penalty and still eat pork?" Here's a few helpful points on the relationship between Christians and the OT law.
1) Some of the OT cleanliness and ceremonial laws were instituted by God for the children of Israel to remain healthy and separate from the surrounding pagan cultures. Remember, there was no FDA or Infectious Disease Center back in bible times. Also, things like tatoos were a mark of murderous, pagan worshippers in those days and so the children of Israel needed to show their separation from such peoples.
2) The Nation of Israel lived in a different governmental relationship with God than any other nation at that time, and throughout all of world history. With apologies to Ronald Reagan, the USA is not a "city on a hill" (that's the church, by the way). Some of the "separation" that was required of Israelites is unique to that era.
3) Regarding food laws. . the shellfish thing. . . .(kosher laws don't allow eating shellfish, . . probably for hygenic/health and ceremonial reasons) Here are a few texts that any responsible bible critic could easily read, explaining the change that Christ brought to the Kosher system:
18 And he said to them, “Then are you also without understanding? Do you not see that whatever goes into a person from outside cannot defile him, 19 since it enters not his heart but his stomach, and is expelled?” (Thus he declared all foods clean.) 20 And he said,“What comes out of a person is what defiles him.
Acts 10:9-16 Peter's Vision
9 The next day, as they were on their journey and approaching the city, Peter went up on the housetop about the sixth hour to pray. 10 And he became hungry and wanted something to eat, but while they were preparing it, he fell into a trance 11 and saw the heavens opened and something like a great sheet descending, being let down by its four corners upon the earth. 12 In it were all kinds of animals and reptiles and birds of the air.13 And there came a voice to him: “Rise, Peter; kill and eat.” 14 But Peter said, “By no means, Lord; for I have never eaten anything that is common or unclean.” 15 And the voice came to him again a second time, “What God has made clean, do not call common.”16 This happened three times, and the thing was taken up at once to heaven.
4) The arrival of Jesus changed everything in regards to the OT ceremonial and dietary laws. The ceremonial laws, Jesus completed (he was the new temple, the sacrifice, the lamb, the priest, etc. . . ) The Dietary laws he fulfilled by upping the ante (what comes out of a person. . not what goes in, defiles him).
5) The Moral Law, (summarized in the 10 commandments) are all repeated in the New Testament at various places, save for the Sabbath requirement. That's how we know those commandments still inform the life of the Christian. That's also how we know the Bible is very clear on every issue of sexual immorality. Those particular Levitical codes are repeated in the NT, (Rom. 1:18-30, 1 Cor. 6:9-10, Matthew 19:4-5) albeit, without the death penalty for adultery or homosexuality, because again. . . we're not living in theocratic, separated Israel. Good rule of thumb: Is it repeated by Jesus or in the NT? Then it's still important.
So, please don't be thrown by the "shellfish" argument. The argument is unfamiliar with the actual text and storyline of scripture.
To summarize, Christians read the bible as having an Old Covenant and a New Covenant because that's how the Bible tells us to read it. So, yes, things have changed. Parts of the OT are understood differently now than they were then, and that's because Jesus told us to understand it that way. I hope we'll be encouraged to read up on issues like this, or ask a Christian friend before being swayed by an argument about scripture that isn't actually familiar with scripture. Thanks be to God for the New Covenant in Christ! What freedom and clarity this covenant brings.
10 For this is the covenant that I will make with the house of Israel
after those days, declares the Lord:
I will put my laws into their minds,
and write them on their hearts,
and I will be their God,
and they shall be my people.
11 And they shall not teach, each one his neighbor
and each one his brother, saying, ‘Know the Lord,’
for they shall all know me,
from the least of them to the greatest.
12 For I will be merciful toward their iniquities,
and I will remember their sins no more.
13 In speaking of a new covenant, he makes the first one obsolete. And what is becoming obsolete and growing old is ready to vanish away.