In this first Psalm, the inner meaning is pretty close to the surface.

Verses 1-3 are saying that people who make it a habit to avoid doing evil things can be led by the Lord, through the Word, to love good things. They will be reborn, or regenerated.

In verses 4-5, it's saying that people who don't live well - who are ungodly - will not be saved.

In Verse 6, the meaning is that the Lord knows us all, interiorly.

There are at least four important truths about our spiritual development here:

1) It's clear that our actions, our habits, are vital. There really are spiritual consequences.

2) We can't "grab good" for ourselves, but we CAN stop doing evil things. That clears up some space for good to flow in, from the Lord.

3) The Lord wants to save everyone; He's constantly trying to lead us towards good. But - since human freedom is so fundamentally important - we are free to reject His leading, and to be ungodly, and, ultimately, to reject His salvation.

4) When we die, the loves that we have built up here on earth stay with us; they ARE us. If they're good, we find a place for ourselves in a heavenly society; if they're evil, we gravitate towards a hellish society of people who have similar loves to ours.

Here are a few of the fine points:

"Blessed be the man". When people receive the Lord's blessing, it illustrates how His love and wisdom flow into us in forms that fit the spiritual state those people represent.

"...in the internal sense 'blessing' means being enriched with all spiritual and celestial good, a blessing which neither does nor can possibly exist unless it comes from the Lord." Arcana Coelestia 981.

"Sitting in the seat of the scornful" implies making a habit of looking down on other people. The word 'sit' is used because 'sitting' means remaining in a state; for movement from one place to another means changes of state involving the interiors, as becomes clear from what has been shown in Arcana Coelestia 2837, 3356, 3387, 4321, 4882, 5605, 7381, and therefore sitting down means remaining in a state involving the interiors. Because 'sitting' has this meaning it was an accepted religious custom among the children of Israel to sit whenever they represented a state of the interiors that was permanent, as in the Book of Judges. Arcana Coelestia 9422

3356. The reason 'a quake' means an alteration of state is that a quake occurs within the space-time continuum, and in the next life there is no concept of space and time, but instead of these the concept of state. In the next life it does indeed appear as though all things exist within space and follow one another in a time-sequence, but in themselves they are alterations of state, for space and time there are the products of these. This is very well known to all spirits, even evil ones, who by means of alterations of state effected in others cause them to appear somewhere other than where they in fact are. Man too is able to know of this from the fact that insofar as his state is one of affection and therefore of joy, or insofar as it is one of thought and therefore of withdrawal from the body, he is outside time. For while such a state lasts, many hours seem to him to be as scarcely one hour. The reason for this is that states belong to his internal man, which is his spirit, to which states intervals of space and periods of time in the external man correspond. 'A quake' therefore, being one of the consecutive events that occur within space and time, in the internal sense means an alteration of state.