Meritorious legalism is the belief that one can legally justify himself before God on the merit of his self-sanctifying performance of law and good works. When sin occurs, the self-sanctifying legalist assumes that He can atone for his violations of law through meritorious good works. The legalist assumes, therefore, that his salvation is centered around his ability to perform law and do meritorious deeds in order to stand justified before God. He thus seeks to earn his salvation by putting God in debt to save him because of his self-sanctifying meritorious law-keeping and good works.
Combined with traditional religious codes, the traditional legalist has constructed a religion that conforms to his desire to justify himself before God through perfect law-keeping. The result of this thinking moves the legalists into numerous erroneous conclusions. Principle among these is the fact that religious legalists often move their traditions into the realm of law, and thus, make their traditions meritorious requirements for salvation. The result is that the legalist moves himself further away from the commandments of God. Because he has assumed that he can meritoriously justify himself before God through law-keeping, he often arrogantly sets forth his religious deeds before others in order to manifest his religiosity and self-imposed righteousness.
When Jesus began His ministry among the Jews, the fury of the religious leaders was inflamed against Him because He did not conform to their legal codes of Judaism. He was thus rejected as the Messiah of Israel. The intensity of the legal mentality of the religious leaders was manifested in their scheme to murder Jesus, which thing they eventually did.
Therefore, one must never underestimate the control religious legal thought places on the behavior of people. Judaism was a religion that was based on the theology of meritorious religious behavior. This was the religious environment into which Jesus came. It was the leaders of this theology that put Jesus on the cross. It was the leaders of this theology who defiantly continued to oppose to the preaching of the gospel.