Why is it important for Christians to exercise their faith?

Paul exhorts Timothy to be an example of the believers in various aspects, including faith, in 1 Timothy 4:12. This not only encourages personal spiritual growth but also serves as a testimony to others. By exercising faith, Christians demonstrate reliance on God and His promises, which leads to a deeper relationship with Christ. Moreover, exercising their faith amidst challenges prepares them to encourage and support fellow believers, thereby fulfilling the communal aspect of faith in a Reformed understanding of the Church.