Even the Pharisees and the Sadducees needed repentance

The gospel of repentance and remission was FIRST preached to ALL the chosen Jews and continued with the commission of the Apostles (Acts 1:8).

Many Jews, among them even MANY Pharisees and Sadducees, got baptized and, thus, were able to recognize Jesus as their Messiah YHWH unlike those of them who rejected the baptism of John the Baptist (Luke 7:29-30). In other words, there is no shame for the modern Jewish Pharisees and Sadducees to repent and believe in Jesus as the Savior, Redeemer, YHWH the Holy One of Israel (Romans 10:9-11). 

Whatever our core belief has been, we, all the Israelites and Gentiles, must repent and submit our theological babblings to Moses and the Prophets (Luke 16:29-31) for validation unto real salvation by following AFTER Jesus (Matthew 10:38).

Not all the Jews rejected the repentance message of John the Baptist and of Jesus. Those baptized elite believers did not prevent the Jewish nation from having been uprooted out of Israel because of the principle of James 2:10. All Israel must have repented for God to intervene and deliver them as it was also the case for Nineveh, when even the animals were fasting.

Matthew 3:5-9 ASV
(5)  Then went out unto him Jerusalem, and all Judaea, and all the region round about the Jordan; (6)  and they were baptized of him in the river Jordan, confessing their sins. (7)  But when he saw many of the Pharisees and Sadducees coming to his baptism, he said unto them, Ye offspring of vipers, who warned you to flee from the wrath to come? (8)  Bring forth therefore fruit worthy of repentance: (9)  and think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham.

We repent to become a new holy creature (a saint), without sin, upon baptism

When we repent of all our sins to agree to live without sins which we left behind to not go back to them, we become a brand-new creature, that is, instantly perfect (because all our sins just got forgiven by Jesus) and instantly holy (because all of our sins just got forgiven by Jesus).

We instantly became perfect, blameless, righteous, or holy because Jesus already paid for the past sins we just stopped sinning.

Satan and his disguised ministers falsely claim that holiness (sanctification) is not about keeping a bunch of rules. If you know anything about God, it always has been about keeping his rules, aka commandments, since Adam and Eve crossed Them to obey the counter advice of Satan instead of the commandments of God.

If we became a brand-new Christian or creature when we joined a church that practices not Judaism 100% as Jesus implies it in John 4:20-22, we are not holy (saint) upon baptism because salvation is not from Christianity and from the Protestants which break from Judaism in at least one iota (Matthew 5:17-18).