In the first part of the final verse, you hear the echo of the beginning of the Psalm: blessed is the man (the word “asrê” = richly blessed). It is certain that the Lord knows who are his (see 2 Timothy 2:19). He cares for those who love him and who desire to keep his commandments. Through God’s protection they feel themselves richly blessed. This encourages them to face the difficult times in life. After all, a life that never ends awaits them (compare the narrow gate to life,
Matthew 7:14). How different it will be for the wicked. They are headed for destruction (Matthew 7:13).
For the readers, it is alarming that the psalm closes with this. For at one point, it will end very badly for those people who shove God’s commandments aside in their earthly lives. Whoever does that, ruins his life for ever. Jesus gives a similar warning at the end of his impressive Sermon on the Mount (Matthew 5-7). There he tells a story of two builders. The one builds his house on the rock, the other one builds on the sand. The one house keeps standing despite the storms that are raging, but the other house becomes a pile of rubble (Matthew 7:24–27). The important question is therefore: on what foundation do we build our house of life? Do we seek our contentment with God, and are we wise by seeking the protection God's law gives? Whoever does that is to be praised eternally. But woe, for those who do not do that. Their life ends in destruction.
6 for the LORD knows the way of the righteous, but the way of the wicked will perish.