We once regarded Christ according to the FLESH

[TonyChanYT]

2 Cor 5:

16 So from now on we regard no one according to the flesh.

I.e., according to our fleshly eyes. We are to look deeper. We now have spiritual eyes/insights.

Although we once regarded Christ in this way,

We thought Christ was only a human being. We looked at Christ from human wisdom's point of view. We have moved beyond this limited view.

we do so no longer.

Now, we can look at Christ with spiritual eyes/insights.

We go beyond the human/fleshly (horizontal) perspective and into the spiritual (vertical) perspective.