So, I'm going to express in few words of what I understand by Gita and this is best done by the last shloka, also known as Eka-shloki Gita, meaning Gita in a single verse!
यत्र योगेश्वरो कृष्णो यत्र पार्थो धनुर्धरः। तत्र श्रीर्विजयो भूतिर्धुवा नीतिर्मतर्मम्॥18.78**
yatra yogeshwarah krishNo, yatra partho dhanurdharah
tatra shreervijayo bhootirdhruvaa neetirmatir mama ||18.78||
What this would mean, literally, is: wherever there is an archer like Arjuna and wherever there is the Lord of Yoga, Krishna, there will be prosperity, victory and happiness; such is my conviction.
The meaning to be seen en passant: wherever one makes oneself a devotee like Arjuna, there will be Krishna to guide and take one across all boundaries and liberate.
The entire Gita is actually a dialogue between the soul as Krishna and the mind as Arjuna! The finally understood meaning is thus: when the mind surrenders unto the soul, renouncing everything, the way Arjuna did unto Krishna, the soul merges into brahman and what is known as liberation results.
om shantih shantih shantih