This means that it is not the children born in the course of nature who are God's Children, but it is the children born in fulfillment of the Promise who are to be regarded as Abraham's descendants.

If you were cut off from your natural stock--a wild olive-- and were grafted, contrary to the course of nature, upon a good olive, much more will they--the natural branches--be grafted back into their parent tree.

The right course is to abstain from meat or wine or, indeed, anything that is a stumbling-block to your Brother.