Notice, Paul does not say, "by what every part or member supplies," but "every joint." For example, a rickety table, feeble in its loose-fitting joints, becomes too wobbly once more than two legs are loose. There may be nothing wrong with the table's legs and the table top. But a table's stability is provided, not by its individual parts, but by the quality of its joints. Unless the legs are affixed securely to the table top, the table is useless.
