VERSE 29. And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise. "If ye be Christ's" means, if you believe in Christ. If you believe in Christ, then are you the children of Abraham indeed. Through our faith in Christ Abraham gains paternity over us and over the nations of the earth according to the promise: "In thy seed shall all the nations of the earth be blessed." Through faith we belong to Christ and Christ to us.