Greetings Vimal - you asked...

I wonder what's the difference between higher self infusion, Merkabah activation, twin flame connection and following the soul are. To me at this point, it all feels the same. But maybe there are some subtle differences?

Actually the differences are pretty major.

In the Openhand Approach, the Twin Flame connection is that between the two polarities of the soul - The Twin Flame remaining close to the source as the other polarity of the soul Incarnates.

The Higher Self activates and then can be infused through concetrated attention. What this means is that the soul is infusing through the higher chakras into the various vehicles of the Higher Self: Higher Mind, Celestial Body and the Spirit Light Body. So the Higher Self is the embodied infusion of soul into those dimensional layers.

We can then speak of "infusing the Higher Self" into the Lower. Actually what happens is a progressive resonance between the various dimensional vehicles as they become active. We can say soul energy is first dripping in through the layers, until it is cascading in.

As this infusion becomes more intensive, then the Merkabah takes form - which is the combination of all the Lower Self and Higher Self vehicles working in unison.

Open 💎