I am not familiar with Willard or Spencer. I am not a Calvinist, but I do enjoy Piper and MacArthur. I believe it is entirely possible that your friend has misunderstood their writings. I certainly hope that this is the case. I hope to take this subject farther sometime next week.
I am remodeling a home, so I may not post it until Tuesday or Wednesday. Keep in touch.
Paul Findlay
Isn't it precisely because God is sovereign that we pray?
The problem is what we mean by "sovereign".
I have a friend who has always been reading calvinistic literature (John MacArthur, John Piper). And the effect on him has been to deaden his desire to pray. Whether that should be the case or not we will leave aside, but for him reading Dallas Willard and the interviews Michael Spencer (aka internet monk) had with a Lutheran have changed things experientially for the better.