The New Testament paints a pretty grim picture of humanity, making us out to be inherently flawed in our ability to serve G-d without transgressing the Torah. In his epistle to the Romans, the apostle Paul plainly lays out his opinion on the nature of mankind. Romans 5:19 says: "For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous." His case here is essentially that because Adam, the first man, sinned, all of humanity is literally born enslaved to sin. This idea that humans are born with a "sin nature" will sound familiar to you if you've ever been in a church service, it's all over the letters of Paul, and Paul's Epistle to the Romans has done more to shape Christian theology than any other book in the entire Christian Bible. Let's be honest here, churches love the book of Romans because it shows that mankind is depraved to the point that we are stained so irrevocably by sin that we are condemned to an eternity in hell just by being born, and to think any other way would contradict Romans. It's so lovable to churches because the New Testament clearly explains that the only way to pardon this sentence of eternal hell is through Jesus/Yeshua. The Gospel of John (3:18) clearly tells us this: "He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of G-d." Those are the words of Jesus/Yeshua himself, according to the Gospel, so it's not like Paul invented new doctrines here. There is some debate among Christian scholars about people who never had the chance to accept or deny Jesus/Yeshua, but I think the Gospel of John made it pretty clear. Paul makes it clear that all humanity is enslaved to sin (Romans 7:14) and in desperate need of Jesus/Yeshua to save us from our sin nature (Romans 3:23-26), and Paul even goes to the extreme of saying that humanity is literally unable to not sin (Romans 8:7-8). Paul goes even further to the extreme and says that it is impossible for a person to understand his inherent need for Jesus/Yeshua without the Holy Ghost (1 Corinthians 2:14), and the Holy Ghost can only come into a person after he has accepted Jesus/Yeshua (1 Corinthians 12:13). So basically the point the New Testament gets across is this: You were born enslaved to a sinful nature which carries the punishment of an eternal hell, even though you never willingly chose to be born and you never knew that the price of living even the most poor and miserable life would be an eternal misery beyond understanding. Before you even sinned for the first time, you were already born destined for eternal hell. It's not like you can go your entire life without sinning, you are enslaved to it and will always have to sin because of your sin nature. There is only one way out -Jesus/Yeshua- but you will never learn this on your own, you need the Holy Ghost to make you aware of this inherent need for Jesus/Yeshua. But you can't obtain the discernment of the Holy Ghost before you accept Jesus/Yeshua. If you never choose to accept him, you will burn in hell eternally because of the way you were born. Even if a baby dies the same day it's born, it is so polluted by its sin nature that it will burn in hell forever because it never accepted Jesus/Yeshua. As I said earlier, the New Testament paints a very grim picture of the nature of mankind. If this is true, then G-d is a sick, twisted being, and I would never consider serving Him for a second because there is no justice in Him.
But what does the Torah say about mankind? If the New Testament is really just a continuation of the Tanach, it should say the same things about the nature of man. Would it surprise you if you learned that the Tanach teaches the exact opposite of the New Testament?
The Torah tells us that humanity was created in the image of our Creator (Genesis 1:27), and we are not born enslaved to sin, this is in the very first parashah of the Torah, it must be true if the rest of the Torah is true. When Cain and Abel brought their offerings to G-d, and G-d rejected Cain's offering, He told Cain the following (Genesis 4:7): "If you do well, will you not be accepted? And if you don't do well, sin waits for you at the door. It desires you, but you are able to dominate it." G-d actually told Cain that he was not enslaved to sin, but he could be dominant over sin. That's far from Paul's claim that we are enslaved to sin, in fact, it means that sin can actually be our slave. We can force our sinful desires to sit in a corner and never even speak to us, that's literally the Word of G-d to humanity. G-d goes even further in the Torah and says that He places before us good and evil, life and death. He then encourages us to "choose life" (Deuteronomy 30:15-20). G-d even outright tells us that the choice isn't too hard for us, it's not distant from us, it's within our hearts and mouths so that we can make the right choice and keep the Torah (Deuteronomy 30:11-14). The Torah tells us that we are not sinners who are enslaved to sin and are incapable of keeping from sinning. G-d Himself says that we are individuals who were created in His image that have the power of refusing to sin, though sometimes we may sin. But even when we do sin, G-d actually gives us instructions in the Torah to put us in a righteous relationship with G-d again. So what need does a person created in the image of G-d with power over sin have for Jesus/Yeshua? Absolutely none, we have no need for Jesus/Yeshua, G-d has already shown us the way some 1,300 years before the apostle Paul ever tried to claim we needed Jesus/Yeshua.
So who are you going to believe? Are you going to accept the grim teachings of Paul that contradict the Torah? Or are you going to accept the words of G-d Himself in the Torah?