Yes, to receive constant and relevant revelation you need the Gift of the Holy Ghost, though you can receive revelation without the Gift of the Holy Ghost at certain times.  
 
To understand this better you must understand the nature of the Holy Ghost. The Holy Ghost is the Third Member of the Godhead he is a personage of Spirit and while he can only be in one place at a time his influence can be felt every where.  
 
Anyone seeking truth can get momentary inspiration from the Holy Ghost it assist them in finding spiritual truth, to have the constant companionship of the Holy Ghost though requires one to have the Gift of the Holy Ghost conferred to them by one with the Priesthood Authority to do so.  
 
The best way to describe it that I have heard of is the following, imaging your walk through this mortal life is a uneven path that is enveloped in darkness. There is no way to see where the pitfalls and snares are to trip you up in the darkness.  
 
The Holy Ghost can be like a magnificent lightning blot to you in this time, it illuminates the whole area but only for a few seconds and then it cannot tarry any longer.  
 
You can use this illumination though to guide you to the waters of baptism and the Gift of the Holy Ghost. Once you have the gift of the Holy Ghost it is like having a flashlight or torch. It is a constant light to you to show you the way on the rest of your journey, if and only if you stay worthy of that gift!  
 
I hope my explanation an my parable helps you understand this concept better.