Measure the Biblical costume wearer's height in inches from the neck down. Take the measurement from just below the chin down to the wearer's feet.
Cut a piece of fabric that won't fray, such as a cotton-polyester blend, to form the tunic portion of the Biblical costume. Make the width of the fabric equal to the height measurement you took in Step 1 and make the length double that same height measurement.
Cut a hole in the middle of the fabric you just cut for the tunic. Make the hole circular and large enough to slip over the wearer's head.
Cut a strip of fabric between 5 and 12 inches wide to serve as a belt for the Biblical costume. Use a slightly different color of fabric for the belt to give the costume greater visual interest. Cut the strip long enough for the costume wearer to tie it around his waist and still have several inches of the belt hanging down the side of the tunic.
Cut a piece of fabric approximately 75 percent smaller than the piece you cut for the tunic. This will be the head cover for the Biblical costume.
Assemble the costume. Slip the tunic over the person's head, tie the belt around his waist and place the head cover on his head.