There is no need to reject Qur'an any more than the Old Testament.
Many of its verses and chapters were revolutionary in the days when pagan Arabs buried alive their
baby daughters because they preferred male children, but are superseded now through the grace of God.
(Whenever sin abounds, the grace of God abounds even more.)
I see no problem in studying the Holy Bible, the Noble Qur'an, the wise Bhagavad Gita and Sun Tzu.
Even Qur'an says (Qur'an 2:62 Al-Baqara):
62. "Those who believe, and those who are Jewish, and the Christians, and the Sabeans
—any who believe in God and the Last Day, and act righteously
—will have their reward with their Lord; they have nothing to fear, nor will they grieve."
So be blessed in studying the Holy Bible, believing in One God, praying, giving tithes and charities to
the poor and the needy.