"Be careful not to forget the Lord, your God, by failing to keep his commandments and ordinances and statutes which I enjoin on you today: lest, when you have eaten and are satisfied, and have built fine houses and lived in them, and your herds and flocks have increased, your silver and gold has increased, and all your property has increased, you then become haughty of heart and forget the Lord, your God, who brought you out of the land of Egypt, that house of slavery; he guided you through the vast and terrible wilderness with its saraph serpents and scorpions, its parched and waterless ground; he brought forth water for you from the flinty rock and fed you in the wilderness with manna, a food unknown to your ancestors, that he might afflict you and test you, but also make you prosperous in the end. Otherwise, you might say in your heart, “It is my own power and the strength of my own hand that has got me this wealth. Remember then the Lord, your God, for he is the one who gives you the power to get wealth, by fulfilling, as he has now done, the covenant he swore to your ancestors.” (Deuteronomy 8:11-18)
"Understand, then, today that it is the LORD, your God, who will cross over before you as a consuming fire; he it is who will reduce them to nothing and subdue them before you, so that you can drive them out and destroy them quickly, as the LORD promised you. After the LORD, your God, has thrust them out of your way, do not say to yourselves, It is because of my merits that the LORD has brought me in to possess this land; for it is really because of the wickedness of these nations that the LORD is driving them out before you. No, it is not because of your merits or the integrity of your heart that you are going in to take possession of their land; but the LORD, your God, is driving these nations out before you on account of their wickedness and in order to keep the promise which he made on oath to your fathers, Abraham, Isaac, and Jacob. Understand this, therefore: it is not because of your merits that the LORD, your God, is giving you this good land to possess, for you are a stiff-necked people." (Deuteronomy 9:3-6)
The Lord promised that He was going to grant His chosen nation Israel unfathomable blessings. He ensured that the Jewish people would remain prosperous. God wanted to continually protect His people. God wanted to continually provide for the needs of His people. He was not, however, carrying through with His oath to their ancestors because of praiseworthy behavior. Rather, He was working things to His glory. God was not blessing Israel because of its righteousness, for the Jews were indeed rebellious against Him. He was accomplishing great things on their behalf in spite of their unrighteousness. He wanted the Jews to place their trust in Him. This testifies to the graciousness and mercy of the Lord.
Likewise, God offered up His Son Jesus Christ as a sacrifice to make atonement for our sins. He did so, not because of any righteousness that we have, but in spite of our unrighteousness. We have all sinned against Him. Thus, we neither deserve His grace nor His salvation. None of us are worthy of entering the kingdom of God. His offer of eternal salvation is available without cost to all who come by faith. Justification is not accomplished by our merits and power, but by the Lord. He wants us to lean on Him. He gives to believers His righteousness. He is saving us because He is gracious, loving, and merciful. There is no room for Christians in this framework to boast. The New Testament emphatically imparts to us this spiritual truth (Ephesians 2:4-9; Titus 3:4-7).
This is evidence that the Old Testament does not teach justification by works, as is erroneously believed by some. Additionally, the Levitical sacrificial system is supportive of vicarious atonement. In the Old Testament, lambs, bulls, and goats were offered to take away sins as an innocent substitute. These sacrifices were done on behalf of the sinner. The animal paid for the guilty person with its own life. These sacrifices are representative of what Christ accomplished on the cross at Calvary. He is the unblemished Lamb who takes away our sins (John 1:29).