The world you see around you is made of matter. The objects and bodies when broken down are just clumps of atoms obeying inert mechanistic laws.
But you (the being you call “I”) are a point of attention, at the centre of it all. Turn your attention within more, and you too will realise that you are made of pure consciousness, not matter.
Sure, the intelligence I am can observe my body, so, yes, that body is in the the world, and is made of matter. But I, the awareness observing it all, am not.
Hence ‘I’ am in this world but not of it.