With the busy topic lately of "Is the entire Bible true?" I'd like to say this: To the unbeliever, no amount of evidence or persuasion will suffice. To the born-again Christian, no more is necessary; plenty exists already.
Abstaining from certain foods was an Old Testament requirement. The New Testament says all foods are permitted. Both are true, but there is a timing issue. Since certain foods were considered unclean, the practice of abstaining was symbolic and pointed futuristically to a time when cleansing from sin and uncleanness would come. Jesus fulfilled that with His sinless death on the cross; therefore the old practice no longer has value.
Homosexuality, slavery and polygamy always have been wrong. It is man who has chosen to ignore that. Jesus did not address slavery because He was fulfilling a much larger purpose of redemption and of challenging people on the state of their eternal souls, not getting caught up in every single thing to which he could have called attention.
Honoring the Sabbath is still correct. Christ reiterated that. Honoring God in one's heart is the most important. Do people honor it? Not most. Is that God's fault? I don't think so. It is mankind that has made it difficult to do with our busy schedules. My hat is off to the Chick-fil-A-ers of the world!
Most folks who keep pointing to these alleged discrepancies do not understand the purpose and timing behind some of these Old Testament requirements nor the fulfillment Christ finished, and thus why it is no longer applicable in the New Testament. They just see a discrepancy.
But it's like passing a baton. Once runner No. 2 has it, runner No. 1 has finished his purpose and all eyes are now on runner No. 2! Same run, though -- same race, same purpose.
North Augusta, S.C.