A vision is for the future and it requires faith; in fact, A vision can be compared to faith itself. The lord instructs us to write it out because Faith is the substance of things hope for and the evidence of things not seen. It's for the future and its unseen but when you make that outward declaration of writing it out it becomes more visible. It becomes the evidence of the unseen. When you write your vision out you not only inspire and motivate yourself but you do others. The bible says that whomever reads it may run. Not physically but it provides the encouragement to persevere.
Sometimes we choose not to write it out and then we forget. Habakkuk 2:3 says the vision is for appointed time so you have to prepare yourself. Write out the revelation/ dream/ vision and position yourself for the manifestation. It may tarry but don't give up because you don't see it immediately. Miracles occur immediately but a vision is a process. There are lessons to learn through out the process. These lessons ensure growth for the appointed time. In the end it shall speak and not lie. It will surely come and not tarry.
Take a look at Sarai, She was a visionary. She had a vision but didn't know how to execute it. She saw children in her future. This I know because The first introduction we got of her was that she was barren but she was also a wife that desired to be a mother (Gen 11:30). I believe the fact that they mentioned her being barren says she attempted to conceive but was unable to.
Can I encourage you today that if you have dreams and aspirations begin to write them out. Sometimes we have to move beyond our mental checklist and write the thought out. It brings you closer to the vision. Don't just write it out and never look back at. Revisit the vision and Spend time with God. Allow him to give you ideas and updates on the process so that there aren't any miscarriages or still birth. Do an evaluation to See what has worked in terms of bringing you closer to the vision. Check what's already accomplished and ask God what's the next step.
Be encouraged, be inspired & be blessed