Free will is regulated by the evolution of the soul

In the face of sufferings and difficulties, most of us inevitably find ourselves in the prison of anxiety, fear and apprehension.
These negative thoughts hold the mind in bondage, depleting its freedom and taking away the ability to think freely and flexibly.
Because there is very little freedom of the mind, we forget about (or disbelieve) the spiritual promises and guidance, and lose the ability to use the spiritual laws and promises. Thus, we are expressing only a tiny portion of our innate power of the spirit. We are unaware of this fact itself, not to mention understanding it, says Silver Birch.

Let's take a look at some quotes from Silver Birch, and consider further on the titled theme: “Free will is regulated by the evolution of the soul.”

A) “All of us—and I say this of myself, too—grope in the dark, seeing sometimes a flash of light and an insight into the Law. We wonder, but, because when we are in the dark, we do not see the Law, we think of chance, we think of accident. I tell you there is no chance.
I know you will say: ‘But what about free will?’ Yes, you have free will but is not your free will subject to the evolutions of your soul? It is free, but its freedom is regulated by your soul’s growth.”
(p.67-68 Teachings of Silver Birch)

B) “The higher you evolve in the spiritual scale, the greater can you exercise your free will. You are your own limitation, but, because you are part of the Great Spirit, you can conquer all the difficulties and obstacles in your world.”
(p.73 Teachings of Silver Birch)

C) “Do not despair. Remember there is no difficulty or obstacle that crosses your path that is so strong that you cannot overcome it by the use of the latent powers that you have within you. Even the difficulties that others place in your path can be swept aside if you will but allow all that is within you to rise and become the master. Your world does not understand that you express so little of yourself while you are in the world of matter.”
(p.113 Teachings of Silver Birch)

D) “If you would but allow that divinity which is within you to rise to the surface, if you would but learn the laws which are responsible for the full flowing of power and inspiration from higher spheres, you would begin to live as the Great Spirit intended you should.”
(p.43 Wisdom of Silver Birch)

E) “When you do not know which way to turn, stop and relax. Ask for that which will sustain you and will carry you forward once more. There is no limit to the help, the power and the inspiration that will come to you if you will have complete trust and faith in us.”
(p.153 Teachings of Silver Birch)

F) “Because the people of your world have not the faith, then the Law cannot be put into operation.”
(p.54 Teachings of Silver Birch)

[Consideration]
As the trust in the Law elevates, there will be less fear, worry and anxiety; and the mind, relieved from these disturbances, enjoys greater freedom. Namely, when we have more faith, we have more inflow of the spirit power and inspirations from higher spheres of the spirit world; more wisdom and enlightenment will follow, along with deeper awareness and understanding of the Spiritual Law. As a result, we are set free from the jailhouse of worry, anxiety and fear.
Growth of the soul brings about elevated faith, and expanded range of freedom to exercise free will.

Let’s review what we have just read. A to F assigned below, corresponds with the respective quote above, with the same alphabet.
A) Your free will is regulated by your soul’s growth.
“It is free, but its freedom is regulated by your soul’s growth.”
Evolution of the soul determines the amount of free will allowed. Although we call it “free” it is dependent on, and is regulated by soul’s growth level.

B) We are part of the Great Spirit.
“Because you are part of the Great Spirit, you can conquer all the difficulties and obstacles in your world.”

C) We are expressing so little of the power we possess.
“Remember there is no difficulty or obstacle that crosses your path that is so strong that you cannot overcome it by the use of the latent powers that you have within you. . . Your world does not understand that you express so little of yourself while you are in the world of matter.”

D) Learn the spiritual laws for using the spirit power.
“If you would but learn the laws which are responsible for the full flowing of power and inspiration from higher spheres, you would begin to live as the Great Spirit intended that you should.”

E) There is no limit to the help, the power and the inspiration that will come to you if you will have complete trust and faith in us.
“Ask for that which will sustain you and will carry you forward once more. There is no limit to the help, the power and the inspiration that will come to you if you will have complete trust and faith in us.”

F) It requires faith for the spiritual laws to function.
With perfect faith and confidence in God and his Law, which are based on correct spiritual knowledge, we can use the spirit power and inspirations from higher spheres of the spirit world. (Using the spiritual law)

[Summary]
Because we are part of the Great Spirit, we are naturally capable of surmounting all difficulty and obstacles that we may encounter on earth; and we have the ability to attain perfect peace. However, because we lack awareness of this essential fact (that we are the Great Spirit), we express so little of the power that we possess within. Free will is self-regulated, depending on the level of soul’s growth.
Freedom of the mind is in proportion to the degree of faith in God, his Law, and the spirit guides; and, faith is required, in order for the spiritual laws to function, and for us to use it.

“These are the things your world needs, the simple truths that will enable spiritual, mental and material freedom to come to your world.”
(p.46 Teachings of Silver Birch)


References
Teachings of Silver Birch—edited by A. W. Austen. Edition 2010, first published in 1938. The Spiritual Truth Press, 15 Broom Hall, Oxshott, Surrey, KT22 OJZ.
Wisdom of Silver Birch—edited by Hannen Swaffer Home Circle. Fourth Impression 1956, First Published 1944. Spiritualist Press, 48, Old Bailey, London, E.C.4.