Terry admitted last weekend's 3-1 defeat at West Ham, in which Chelsea took the lead but let in three goals in the last half-hour, was particularly hard to stomach.
"The game on Saturday was hard for me to watch," he said. "We need to be stronger than that and we know we can't let that happen again.
"Let's show some fight and desire for our club and for the shirt. Players will come and go, but what must always remain is the spirit within this club; never give up and fight for every last thing."