This expression refers to the fact, that the Church which is Christ’s body (Eph. 1:23), instead of being one (John 17; Eph. 4:2, &c.), is divided and split up into above 1,000 sects and parties. Of course the fact that al believers form one body cannot be destroyed (hence the “ruin of the body” would be incorrect), but the outward expression of this unity by a once united assembly or Church is gone entirely: hence the expression.