"And I have other sheep which are not of this fold; those also I must bring in and they will listen to my voice, and they will become one flock, one shepherd." (John 10:16)
Fold - a flock of sheep, a group of animals (Merriam-Webster Dictionary)
Since a 'flock' is the SAME thing as a fold, then when the Christ says that the 'other sheep will be brought in, they will be ADDED to the 'fold' or flock' he already had and all sheep will be in the same flock (fold). There is no "two folds" because two folds means two flocks and He said one FLOCK. Hence, all the sheep are together in one flock and all the sheep have one hope, one faith, one baptism.