How is using equity to fun a new property profitable?

[Dennis O'Loughlin]

Can someone please help explain to me how you keep building equity when using equity to fund the down on your next investment? I understand the idea but I can't get my head wrapped around it because when you borrow against the equity you're going to have to get a loan from the bank to do that so you're going to have a payment. If you're not making much beyond 6% ROI on that property you may not be able to cover that payment with all the other expenses. With the mortgage from the new property, if you add the loan for the equity borrow, it may be hard to find a deal good enough to cover both loans. Can someone clear this up for me? Maybe I'm just way overthinking it.