Final answer:
The New Testament writer who stresses that actions should align with faith is the Apostle James, especially in the Epistle of James. Jesus's teachings, as recorded by Matthew and others, reinforce the importance of love and mercy, as well as true expression of faith through deeds. This contrasts hypocritical behaviors of professing love while practicing discrimination, which goes against the scriptural calls for loving one's neighbor.
Step-by-step explanation:
The New Testament writer who emphatically cared that our walk matches our talk is often considered to be the Apostle James. In the Epistle of James, there is an emphasis on the importance of acting in accordance with one's faith. For example, James 2:14-26 discusses faith without works being dead, urging believers to demonstrate their faith through their actions. This is reflected in the insistence that true religion is to look after orphans and widows in their distress and to keep oneself untarnished by the world (James 1:27).
In contrast to the teachings focused on by James, the situation recounted in the first quote points to a hypocritical behavior among Christians who preach love and mercy but practice discrimination and neglect—behaviors that are at odds with the message of Jesus Christ. In Matthew 22:39, Jesus himself cites the second greatest commandment as loving one's neighbor as oneself. This principle is a clear declaration against practices that are racist or discriminatory, and it underscores the New Testament's emphasis on congruency between belief and action.
Throughout the New Testament, several writers, including Matthew and John, highlight the need for genuine love and good deeds, echoing Jesus's teachings on compassion and service to others. Despite the various interpretations and misapprehensions among followers, the core message remains one of love, mercy, and authentic expression of faith.