Is suffering a requirement for those who believe Jesus is the Christ?

Why does God allow a believer to suffer?

"Beloved, do not be surprised at the fiery ordeal among you, which comes upon you for your testing, as though some strange thing were happening to you; but to the degree that you share the sufferings of Christ, keep on rejoicing, so that also at the revelation of His glory you may rejoice with exultation. If you are reviled for the name of Christ, you are blessed, because the Spirit of glory and of God rests on you. Make sure that none of you suffers as a murderer, or thief, or evildoer, or a troublesome meddler; but if anyone suffers as a Christian, he is not to be ashamed, but is to glorify God in this name.   For it is time for judgment to begin with the household of God; and if it begins with us first, what will be the outcome for those who do not obey the gospel of God? AND IF IT IS WITH DIFFICULTY THAT THE RIGHTEOUS IS SAVED, WHAT WILL BECOME OF THE GODLESS MAN AND THE SINNER? Therefore, those also who suffer according to the will of God shall entrust their souls to a faithful Creator in doing what is right." (1 Peter 4:12-19 NASB)

"These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world." (John 16:33 KJV) 

"If the world hate you, ye know that it hated me before it hated you. If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you. Remember the word that I said unto you, The servant is not greater than his lord. If they have persecuted me, they will also persecute you; if they have kept my saying, they will keep yours also." (John 15:18-20 KJV)