But the bible says there is witchcraft and it is an abomination. How can one believe in the Word but not in the entirety of the Word?
The Bible condemns people engaging in hackery--like spirit mediums, astrologers, potion-makers, etc--but at no point indicates that what they are doing is real.
The Church, historically, understood that there is no such power as magick, and those who engaged in "magickal" practice were deluded and delusional. If the devil was involved at all, it was as the deceiver, deluding and deceiving the minds of such people.
The Church has a word for such spiritual hackery, it's called superstitio (superstition) in Latin and deisidaimonia in Greek; in a positive sense deisidaimonia simply means "piety" or "religiously reverent"; but its use in a Christian context tended in use to refer to pagan religious reverence, a false piety, a false religiosity, a false spirituality toward false gods.
In the middle ages as Christianity spread into northern Europe a major issue was the conversion of European pagans, such as when King Charles of the Franks (who would later be known as Charlemagne) conquered the Saxons, the Saxons were Germanic Pagans, and part of the conversion effort was to stamp out belief in superstitions. One of the superstitions among the Saxons was a belief in witches. As such the Frankish Council at Paderborn made witch-hunting a criminal offense (witch-hunting was a pagan thing, not a Christian one, as Pagans, not Christians, believed in witches and witchcraft).
The Canon Episcopi is an old medieval document of uncertain origin that effectively addresses the errors of superstition, such as belief in witches and witchcraft. Assigning powers to anything other than God was a blasphemous heresy. Those who believed in magick, or believed the devil could create life or offer power to people were believing in heretical, blasphemous ideas by ascribing to people, false gods, or the devils powers which only could rightly belong to God.
That was the precedent for most of Christian history until the publication of the Malleus Maleficarum in the 15th century which sought to overturn orthodox Christian opinion to insist that witches really do exist, and the devil really can work miracles and powers through witches, mediums, and so on and so forth. Which is why it is not until the early modern era that we begin to see public opinion in Western Europe change.
This is why the Salem Witch Trials are not some vestigial ignorance held over from the middle ages, but a product of the modern age. Witch Trials were not a feature of the middle ages, they were a feature of the modern era, and often in Protestant, though sometimes in Catholic, lands. The Church of the middle ages knew better than to believe in pagan superstition such as witchcraft and magick and other such hokey hackery.
And so the modern fear of witches that has persisted is likewise pagan superstition, and no Christian should entertain blasphemous and heretical notions such as this. Belief in the power of witches is a pagan belief, not a Christian one.
So, no, the Bible does not teach us that there are people in the world that can perform feats of magick; because the Bible does not teach us that false gods have power, or that the devil can rival God. The devil is a mere creature, with no cosmic power; and false gods are nothing. That is why when the prophets of Ba'al called out to Ba'al nothing happened, but when Elijah called out to God fire came down out from heaven. The Bible is consistent: the gods of the nations are blind, deaf, lifeless idols that are nothing. The gods of the nations are not gods, they cannot hear, they cannot see, they cannot act.
There's a good reason to tell Christians not to get involved in false spiritual practices and hackery, but the possibility of gaining or attaining some actual mystical power isn't one of them. False spirituality and hackery is harmful because it leads us away from the true spirituality that is found in Christ in His Church, the spirituality that comes from hearing the Gospel and receiving the gifts of God's Sacraments. Anything that is placed as an obstacle between us and the Gospel is an obstacle that needs to be removed.
The best way to combat bad spiritual practices is to encourage good spiritual practices; we combat bad theology with good theology, we confess our faith with clarity in our churches. The truth is its own defense.
-CryptoLutheran