I will need to research further if there are historical links with gnosticism and Darby or the Brethren, but it seems Dispensationalism has, primarily through its eschatology, let in a lot of gnostic ideas. I should clarify that Dispensationalism itself isn't necessarily gnostic (at least I cannot currently make that argument), rather it has been a theological vehicle to bring in a lot of Gnostic thought into the Church — emphasis on the spiritual over the physical, a near repudiation of the material world (this is more apparent in some circles than others), minimizing the importance of space/place specifically in worship, *just passing through* mindset, escapism and their specific views on a spiritual heaven over a robust theology of physical resurrection and a new earth, a high time preference and a lack of emphasis on building things that last, etc.

I'll add that one can unknowingly have Gnostic-like ideas as a Christian and not be Dispy or premil, but I see the fruit most often in those circles (I was once in those circles).