Acne returning

Hi I have acne and i've been using this acne treatment (cleanse, tone, day/night cream and matte moisturiser) and my acne will clear up, which is good. However if I just use the cleanser and toner, without the day/night cream my acne will return. Does this mean I have to keep up all the steps for a while? I don't really know what to do, any information would be helpful. Thanks ☺️

(for anyone wondering, or if this is helpful I am using the dermalogica acne treatment stuff)