How do we know effectual prayer works?

The effectiveness of prayer is grounded in the righteousness of the one praying and their dependence on God's grace. James 5:16 emphasizes that the effectual fervent prayer of a righteous man avails much. This righteousness is not of our own doing; it is the righteousness Christ imparts to believers. When we approach God in prayer, relying on Christ's intercession, our prayers become powerful and effective. Moreover, prayer is inherently relational; it reflects our trust and dependency on God to act according to His will, making it potent in effect.