Violence is basically bad; it causes pain, death and violates human dignity. The conception of violence as a liberating good (along with its associated symbols of virility, fire, steel, etc) is a fascist narrative. Recourse to violence can only be justified if no other means is available, the violence can succeed in its aims and we can be sure that by not engaging in violence we would create or sustain a greater wrong.
For socialists, particularly in advanced capitalist society, violence is never the chosen terrain of struggle. Class power relations are asymmetrical. The state has bodies of armed men at its disposal; the left’s power lies elsewhere. It has political organisation, in the economic domain strikes plus other forms of industrial influence and the means of ideological struggle.