Chuck Swindoll made a good point on the obedience of the Israelites.
"My personal conviction is that our greatest struggle is not in the realm of understanding the will of God; it's in the realm of obeying the God whose will it is."
However, what the Israelites were to obey isn't what we are to obey. Jesus changed the rules (John 15:12). We no longer are required to be obedient in our behaviors.
Instead, we are to be obedient in value system - we are to adopt God's value system. God's value system is sacrificial love for the benefit of others - best represented by Jesus on the cross. Rules can't help us become good (Rom 7:10), but God's value system fulfills the law (Rom 13:8-10, Gal 5 -esp v14).
Obedience to rules is a failed system for spiritual growth. It's not even what God wants! (Matt 12:1-12, esp v7 & v12a) God wants our values to be his values because they are the basis for relationship with him. And good behaviors will naturally follow.
Do not think of spiritual success by your obedience. Think of spiritual success by the degree to which sacrificial love for the benefit of others has become your motivating, guiding value system. Thinking this way sets you free even though it is a more difficult challenge. And you will see God change your behaviors to do loving things beyond what was in your nature.