I've heard Pastors who refuse to allow the prophetic ministry into their churches give vague warnings about "false prophets" coming in. Yes, scripture warns us about them but we are also warned about false teachers. Teachers in general  have a heavier judgment because while a false prophet may harm an individual or a church, a false teacher may infect an entire generation with a false teaching that may then be passed down to succeeding generations...repeated till Jesus returns. The same can happen with false prophecy too, but far more churches accept false teachings than they do false prophecies. So, whether false teachings or prophecies, the only safeguard is the Holy Spirit's abiding presence within us. When in doubt - ask him! He delights in leading us into all truth (Jn:16:13).
You can trust him with your whole heart - he will never lead you astray. He will teach you how to recognize his voice so that another you will not follow, and he will do this quickly when you seek him for it - when you seek him in order to know the truth, not to validate what you think is truth. He will expose every lie spoken to you by the devil through men, and he will expose the lies you tell yourself. You will learn to discern what spirit the one teaching you is really of, by becoming intimate with the Holy Spirit yourself. Lastly, may I add, as you get to know the Holy Spirit, you will recognize him in others. Surround yourself with wise counselors, filled with the Spirit...there is safety there...seek out other men and women who know the Spirit, who are full of him.....who bear his fruit, who speak his words....who demonstrate his gifts....remember, the anointing is caught more than it's taught.....