from an article by Dr. Tim Keller of Redeemer Church:
I find it frustrating when I read or hear columnists, pundits, or journalists dismiss Christians as inconsistent because “they pick and choose which of the rules in the Bible to obey.” What I hear most often is “Christians ignore lots of Old Testament texts—about not eating raw meat or pork or shellfish, not executing people for breaking the Sabbath, not wearing garments woven with two kinds of material and so on. Then they condemn homosexuality. Aren’t you just picking and choosing what they want to believe from the Bible?”
Most Christians don’t know what to say when confronted about this. Here’s a short course on the relationship of the Old Testament to the New Testament:
The entire book of Hebrews explains that the Old Testament ceremonial laws were not so much abolished as fulfilled by Christ. Whenever we pray ‘in Jesus name’, we ‘have confidence to enter the Most Holy Place by the blood of Jesus’ (Hebrews 10:19). It would, therefore, be deeply inconsistent with the teaching of the Bible as a whole if we were to continue to follow the ceremonial laws.
The New Testament gives us further guidance about how to read the Old Testament. Paul makes it clear in places like Romans 13:8ff that the apostles understood the Old Testament moral law to still be binding on us. In short, the coming of Christ changed how we worship but not how we live. The moral law is an outline of God’s own character—his integrity, love, and faithfulness. And so all the Old Testament says about loving our neighbor, caring for the poor, generosity with our possessions, social relationships, and commitment to our family is still in force. The New Testament continues to forbid killing or committing adultery, and all the sex ethic of the Old Testament is re-stated throughout the New Testament (Matthew 5:27-30; 1 Corinthians 6:9-20; 1 Timothy 1:8-11.) If the New Testament has reaffirmed a commandment, then it is still in force for us today.
Once you grant the main premise of the Bible—about the surpassing significance of Christ and his salvation—then all the various parts of the Bible make sense. Because of Christ, the ceremonial law is repealed. Because of Christ the church is no longer a nation-state imposing civil penalties. It all falls into place. However, if you reject the idea of Christ as Son of God and Savior, then, of course, the Bible is at best a mish-mash containing some inspiration and wisdom, but most of it would have to be rejected as foolish or erroneous.
So where does this leave us? There are only two possibilities. If Christ is God, then this way of reading the Bible makes sense and is perfectly consistent with its premise. The other possibility is that you reject Christianity’s basic thesis—you don’t believe Jesus was the resurrected Son of God—and then the Bible is no sure guide for you about much of anything. But the one thing you can’t really say in fairness is that Christians are being inconsistent with their beliefs to accept the moral statements in the Old Testament while not practicing other ones.
One way to respond to the charge of inconsistency may be to ask a counter-question—“Are you asking me to deny the very heart of my Christian beliefs?” If you are asked, “Why do you say that?” you could respond, “If I believe Jesus is the the resurrected Son of God, I can’t follow all the ‘clean laws’ of diet and practice, and I can’t offer animal sacrifices. All that would be to deny the power of Christ’s death on the cross. And so those who really believe in Christ must follow some Old Testament texts and not others.”
read the whole article here