It's hard to say "yes" to God when it means saying "no" to yourself, but that is what Christ calls us to do as Christian. Christian means Christ-like. So to be like Christ, we must deny ourselves and embrace the kingdom mission just as Jesus denied himself to fulfill His mission here.
In the garden He prayed to "let this cup pass". He didn't want to go to the cross anymore than we would, yet He desired His Father's will more than His own.
He calls for us to do nothing less!