No matter how terrible they may be, the hardships and tragedies of human living that often befall Christians are not the crosses of which Jesus speaks. Such things as a cruel spouse, a rebellious child, a debilitating or terminal illness, the loss of a job, or destruction of a house by a tornado or flood, may strongly test a believer’s faith; but those are not crosses. The cross of a believer is not a mystical or spiritual identification with the cross of Christ or some “crucified life” idea. Such concepts are foreign to the context, and the cross of Christ was yet future when Jesus spoke here. The disciples would hear cross and think only of physical death. A cross is the willing sacrifice of everything one has, including life, for the sake of Christ. It is something that, like the Lord Himself, a believer must take on himself when it is thrust upon him by the unbelieving world because of his relationship to God.
John MacArthur