A single length of thread will likely not be enough to attach the entire patch.

When there's approximately 3 to 4 inches (76 to 102 mm) of thread left, pull the needle through to the interior of the garment.

Make a secure knot on the backside of the fabric using one of the techniques from Knot Thread to the Fabric (2 Ways) and trim the extra thread.

Rethread the needle, knot both ends of the thread, and restart by coming up from behind the patch just as described in Step 6.