The one big thing that many are missing in saying that ‘sin is sin’; and that ‘all sins are alike’ is that if they agree it is sin, then where is the repentance, and confession to God, asking for forgiveness? What sin do we demand absolution from without repentance?
For you see, to repent indicates to turn away from the offense. True enough that some have besetting sins, but their desire is to repent and turn away from the sin, not to herald it as OK and demand that everyone accept the sin as normal.
When we are saved, this means we Agree with Jesus concerning our need for a savior; we ASK HIM to forgive us our trespasses and cleanse us from ALL unrighteousness; we Believe that He alone provides the cleansing and justification for our sin, and we Confess that He is our Lord! ABC= Ask, Believe, Confess; Simple, yes; but still requiring our agreement with HIM concerning our sin and our need for a savior.
Also true, the sins are not what damns a soul; unbelief and refusing God’s provision is what damns a soul to eternal separation from God. For you are indeed correct, that we all sin. No one is justified by works or keeping the law. All need a savior. But as evidence of becoming a new creation in Christ Jesus, we turn away from sins. It is NOT the desire of a child of God to continue in sin.