Well I disagree with that too. I don't think Christ removes all our internal suffering, not on this side of life. The flesh remains until we die. And the flesh is sinful. We are a new creation if we are in Christ, and we grow and mature and learn to fight the flesh, but it's still a battle since the flesh is still there, and I believe as christians we will grieve because of the flesh and it's sin until we die and that's internal suffering. But because of all that Christ has done for us, because of the gift of salvation and the gift of Himself to us, this great love he has for us despite all our sins, this causes great rejoicing despite internal and external suffering.
Faith, even great faith, does not remove the flesh.