¹¹ And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers;   Ephesians 4:11 KJV

What does the spirit of prophecy means?

• Spirit means the realm of the anointing (that is prophetic in nature).
• Prophecy means to declare. To foretell the future of a person, a nation or a thing.
• Prophecy is (in the realm of the spirit) to say something, to declare about the future.

Not every believer can prophesy the future. The ministry of a prophet is to prophesy the future. 

The gift of prophecy is a miraculous act of intelligible communication, rooted in spontaneous, divine revelation and empowered by the Holy Spirit. The gift of prophecy is a special ability to speak forth the message of God. A prophet is basically a spokesman for God. He or she delivers the Word of God to people by means of direct revelation. The Holy Spirit does not teach the proud, the unteachable, the indolent, or the doubter. A deep desire for truth and faith in the Lord Jesus Christ will prepare one’s heart to be taught spiritual things.

Ephesians 4:11-16

King James Version

¹¹ And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers;

¹² For the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ:

¹³ Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ:

¹⁴ That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive;

¹⁵ But speaking the truth in love, may grow up into him in all things, which is the head, even Christ:

¹⁶ From whom the whole body fitly joined together and compacted by that which every joint supplieth, according to the effectual working in the measure of every part, maketh increase of the body unto the edifying of itself in love.

(Information gathered from various websites)