The law is not a necessary evil in scripture. The evil lies in us (Romans 7). The law tells us what we ought and ought not to do. The law is from God and is good.
What we need is grace, which amounts to God’s undeserved favor given to us in and through Christ. It is a gift that we receive, pure and simple. Through Christ’s death for us on the cross, we are forgiven of our sins when we repent and believe as in entrusting ourselves into God’s hands, and committing our lives to him.
Law necessarily condemns, but in grace there is never any condemnation. Christ has taken all the condemnation on himself at the cross. The Spirit is given to us, and we have the assurance that we are once for all time forgiven. But that doesn’t mean that the law no longer applies to us.
By grace through the Spirit we actually fulfill the requirement of the law, which in shorthand amounts to love, but not without details spelled out in scripture. For example, we don’t love our neighbor as ourselves when we commit adultery, or either do, or fail to do a number of things.
If we’re living under God’s grace, then we’re made both willing and able. And we in Christ are under grace, not under law (Romans 6). Law comes to us in a coercive way: we have to or else. Grace comes on us in a compelling way: we want to, period. Yes, out of love in love. And it’s a want to placed in us by God. As those who are forgiven and given new life in Jesus. To follow on and be victorious. In and through Jesus.