Paragraph 553 
The notion of mind has its reality in the mind. If this reality, in identity with that notion, is to exist as the
consciousness of the absolute Idea, then the necessary aspect is, that the implicitly free intelligence be in its actuality liberated to its notion, if that actuality is to be a vehicle worthy of it. The subjective and the
objective spirit are to be looked on as the road on which this aspect of reality or existence rises to maturity.
To clarify the text I would say the following:
The concept of the mind finds its true existence within the mind itself. For this reality, which aligns with the concept, to manifest as the awareness of the absolute Idea, it is essential that the inherently free intelligence is fully realized in its actual form. This actual form must be capable of embodying the concept appropriately. The development of both subjective and objective spirit should be seen as the path through which this aspect of reality or existence matures and reaches its full potential.
So what is Hegel saying here? Let's break it up into its constituent parts:
1. 
Concept of the Mind: The idea here is that the mind's true nature or essence is found within the mind itself. It's like saying the mind understands itself best.
2. 
Reality and Concept Alignment: For this true nature of the mind to become the awareness of the absolute Idea (a perfect, all-encompassing concept), the mind's inherent freedom needs to be fully realized in its actual form. This means that the mind must express its potential in a way that matches its true nature.
3. 
Inherently Free Intelligence: The mind is described as having an inherent freedom. For this freedom to be fully expressed, the mind's actual form (how it exists and operates) must be capable of embodying this freedom appropriately.
4. 
Subjective and Objective Spirit: These terms refer to different aspects of the mind's development. The subjective spirit is about individual consciousness and personal experiences, while the objective spirit involves shared, societal, or universal aspects of consciousness.
5. 
Path to Maturity: The development of both subjective and objective spirit is seen as a journey. This journey is necessary for the mind's true nature to mature and reach its full potential.
In simpler terms, the text is saying that for the mind to fully realize its true nature and potential, it must develop both individually and collectively. This development is a journey that leads to a mature and complete understanding of the mind's essence.