>> “The Pharisees prided themselves on their “good works”—i.e.,observing the law.” <<
.
Spend some time reading the gospel of Matthew!
The Pharisees had zero respect for Yehova’s law, and obeyed no part thereof, substituting instead their own man made law, which Yeshua completely denounced, declaring that unless one’s righteousness exceeded the false righteousness of the Pharisees, one had no chance at seeing the kingdom.
You seem to take this in the sense of "I must perform more good works than the Pharisees." Christ understood it in this way:
"The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican. I fast twice in the week, I give tithes of all that I possess. And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted." (Luk 18:11-14)
The contrast here is between the Pharisees who glory in their works, in their tithes, their refusal to commit adultery, and their loyalty to the Jewish people, and with the Publican, a tax collector, who does not even think Himself worthy enough to look up to heaven when he prays, but smotes his breast, symbolical of his smashing of his own pride and self-righteousness. The Publican goes down "justified" not because he performs more good works than the Pharisee, or even that his sins were less heinous, but because he recognized himself as a sinner in need of a savior. This is the essence of the Gospel, that a sinner, who cannot be justified by his works, is instead justified by his faith.
As for your objections against Paul's verse. You have not demonstrated how we ought to understand it, but have only pointed us to look at the Gospels, as if there is something there to contradict it. Presumably, Paul's verse cannot contradict something in the Gospel. So, then, can you provide a reading of Paul, using his words, that show he does not believe that the works of the law, so far as receiving justification is concerned, are irrelevant to our salvation?