A larger quote, taken from https://en.wikiquote.org/wiki/Hermann_Rauschning :

It is not Germany that will turn Bolshevist but Bolshevism that will become a sort of National Socialist. Besides, there is more that binds us to Bolshevism than separates us from it. There is, above all, genuine revolutionary feeling, which is alive everywhere in Russia except where are Jewish Marxists. I have always made allowance for this circumstance, and given orders that former Communists are to be admitted to the party at once. The petit bourgeois Social-Democrat and the trade-union boss will never make a National Socialist, but the Communist always will.... Our spirit is so strong, and the power of our magnificent movement to transform souls so elemental, that men are remodeled against their will... A social revolution would lend me new, unsuspected powers. I do not fear permeation with revolutionary Communist propaganda.

This indicates that he believed certain communists could be converted to something non-communist. Especially this part: "[...] transform souls so elemental, that men are remodeled against their will [...]" . I haven't investigated whether Hermann Rauschning was trustworthy or not, however.