The Adventist Church teaches that the Law is how mankind is reconciled to God. And by “Law” they mean the 10 Commandments. They teach that what God gave Moses was written on stone by His literal finger, demonstrating it’s eternality (equating the stone canvas with permanence) whereas Moses’s Law was written on parchment and only contained ceremonial commands and ordinances. They often try to appeal to the Protestant Reformers to support this, but this is a twisting and/or misunderstanding on their part.
The core problem with that SDA teaching on the Law is not that they see the moral aspect of it being binding, but that they put people under it covenantally. They do not teach a distinction between the Law and the Gospel—something which was foundational in the Protestant Reformation. The good news in Adventism is that Jesus came to pay the penalty for sin, showing that God’s Law can be kept perfectly, which silenced the accusations of Satan in the Great Controversy (the key seminal, governing principle of their theological framework) and opened the way for our Law keeping to be able to be meritorious by virtue of Jesus’s work. They view the Law as the measuring stick of who is and isn’t worthy of entering Heaven.
Before being granted eternal life in the New Heaven and New Earth, it is going to have to be shown in the Investigative Judgment that you can be trusted to not let sin enter Heaven again by living a sinlessly perfect life now. Jesus also has to be able to show the watching intelligences that He is just and fair in saving those He saves to show that Satan is an accuser and liar. In order for that to happen, one must have a perfectly spotless record of every sin confessed upon making a profession eventually leading to a point of sinlessness in your current condition. This is supposedly possible now with the help of the Holy Spirit.
While they will be quick to tell you they don’t believe their works save them (which works based system ever does?), they teach that everyone who has professed to be a Believer will be tested up against the 10 Commandments and their perfect obedience to them to see if they are found worthy of having Jesus’s atoning benefits applied to their account. This is a key aspect of their Investigative Judgment doctrine. It’s only by demonstrating a perfect sinless life (the inside baseball term is “a prepared people”) in accordance with the 10 Commandments, especially the 4th commandment (which they teach is the seal of God), that person will be saved.
This is all downstream of their fundamental misunderstanding of the Law Gospel distinction between the Covenant of Works (Law) and the Covenant of Grace (Gospel) which they have intermingled, warping and distorting the Gospel of Jesus Christ.
The Bible teaches that Jesus Christ fulfilled the Covenant of Works perfectly, doing what Adam and Eve failed to do. As the Second Adam (1 Corinthians 15:45-49, Romans 5:12-17) Jesus Christ secured an eternal redemption (Hebrews 9:12) for His people, a people that He knows intimately already (John 10:27). Because of this, He satisfied the demands of the Law and is able to then impute His perfect righteousness to sinners (Philippians 3:8-10) as a gift leaving them seen as worthy “in Christ” (Galatians 3:26-28). Jesus took their sinfulness, bearing it in His body on the tree (1 Peter 2:24), satisfying the requirements of the Law, and freeing Believers from it’s ability to condemn us (Romans 8:1). We can truly say, like Paul the Apostle did, that we have peace with God (Romans 5:1).
Because the Covenant of Works (Law) has been fulfilled by Christ, it has been abrogated (Hebrews 8:13). Jesus came to redeem those under the Law covenantally (Galatians 4:5-7) and set them free from its condemnation.
We are freed from the penalty of the Law by being “in Christ” and, because we are given a new nature when born again, our hearts desires change and we seek to obey and serve the Lord Jesus because of this new desire. Prior to being born again, the Bible teaches that we do not seek for God and do no good (Romans 3:9-11), are by nature children of wrath (Ephesians 2:3), and cannot do what is pleasing to God (Romans 8:8). But in His great mercy, God grants us faith to believe (Philippians 1:29), grants us repentance, which is us turning to Him (2 Timothy 2:25), and through this, adopts us into His family (Ephesians 1:5, Galatians 4:5-7), remembering our sins no more (Hebrews 8:12).
Christian’s do not obey Christ to maintain our righteousness, or show we are worthy of Christ’s atoning benefits (spoiler alert: we aren’t!) or to show that we can be trusted to not let sin enter Heaven again while we are on a period of probation. We serve God because we love Him and out of gratitude for what our LORD has done for us as He continues to sanctify us and make us more like Him.