Firstly,I will raise them up a Prophet....and will put my words in his mouth;and he shall speak unto them all that I command him.Deuteronomy 18:18
Secondly,And he gave some, apostles,and some Prophets and some evangelists and some pastors and teachers.Ephessians 4:11
Thirdly,When a prophet speaketh in the name of the Lord,if the thing follow not,nor come to pass,that is the thing which the Lord hath not spoken but the prophet hath spoken it presumptuously;thou shalt not be afraid of him.
From the above I can safely posit that;
God raises Prophets in their generation by calling them and he gives them prophecies to warn his children of impending dangers.
Also,there are true Prophets and false prophets.Jesus himself warned us to beware of false prophets Matt 7:15.
Lastly, false prophets can speak out of presumption and not really from God.

For this year, the Lord will fulfill his promises in your life according to 2 Chro 20:20, Believe his prophet so shall ye prosper.

Don't let anyone create fear in your life due to negative prophecies.Reject such and read the Bible to claim his word for your life.God bless you.