Let's break this statement down into two parts.
P1. - The Plan
P2. - Trust
Why would I place The Plan before Trust? My reasoning is that this is an actual statement with clear direction to its recipients to take action. In this case, the action is Trust. In order to understand the direction given and reconcile against our personal moral code, we must first understand what is being requested of us.
"The Plan"
What is "the plan"? Does anyone know? Do they really know?
I would first ask that you consider just how grand of a plan you can comprehend? I'm confident you will agree that individuals make plans all of the time. We plan our meals, our wardrobe, dates, reunions, holidays, work assignments, home chores, etc….
Would you then consider how extreme of a plan you could map out? How would you go about planning your entire life from this point forward? Could you devise such a detailed plan that you could effectively pick exactly who you wanted to be and know with absolute certainty that your plan will succeed? There are people out there doing it every day. Hell, (you) do it every day even if you aren't conscious of it.
If you couldn't imagine devising such a plan for your own life, how could you possibly comprehend that another individual (or group of individuals) have planned their lives out with such precision that they are now capable of defending an entire nation of people against others whose mastery of the plan is just as astute?
Now, I beg of you, consider 'God's Plan'. Regardless of your position on God, I ask you only consider God's Plan if for no other reason than intellectual intrigue. How grand of a plan could the origional creator have? Can you even begin to grasp the concept of a plan for every individual as well as the fate of the entire world let alone the execution of said plan?
"Trust"
If you can not plan your own day, how can you ever truly understand "The Plan"?
How can you "Trust" what you don't understand?
In this case, it becomes impossible to comply as no human should be required to trust something they do not understand. However, isn't Faith a synonym for Trust?
Could the statement be read: 'Have Faith in The Plan'?
Can you have faith in something you don't understand?
What if the plan is (You)?
Can you put Faith in yourself?
Trust yourself.
(You) are the plan.
(You) always were.
(You) were a part of (((their))) plan.
No more.
Trust the plan
Dark to light.
Godspeed.
WWG1WGA