Yes its in the bible. But many people have used the whole persecution card to claim that they were true Christians. However every religious group has recieved persecution, and persecuted other religious groups. However it seems like most of the people who cry persecution are only being persecuted for having persecuted others in the first place.
I agree with the OP.
Paul/Saul was a persecutor of the worse kind but he became one of the leading Christians. But not all persecutors become Christians and not all Christians have been persecuted in their life.
So the verse can't be used as proof for anything.
Jacob tricked (persecuted) Esau, then Esau's descendants persecuted Jacobs for a Looooong time, still going on (both ways)
Yet hath he not root in himself, but dureth for a while: for when tribulation or persecution ariseth because of the word, by and by he is offended.
Acts 14:22
Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the "kingdom of God"
Luke 12:53
The father shall be divided against the son, and the son against the father; the mother against the daughter, and the daughter against the mother; the mother in law against her daughter in law, and the daughter in law against her mother in law.
If your own full brother, or your son or daughter, or your beloved wife, or you intimate friend, entices you secretly to serve other gods, whom you and your fathers have not known, gods of any other nations, near at hand or far away, from ...one end of the earth to the other: do not yield to him or listen to him, nor look with pity upon him, to spare or shield him, but kill him. Your hand shall be the first raised to slay him; the rest of the people shall join in with you. You shall stone him to death, because he sought to lead you astray from the Lord, your God, who brought you out of the land of Egypt, that place of slavery. And all Israel, hearing of this, shall fear and never do such evil as this in your midst."