How do we know that God's call is effectual?

The effectual call of God is rooted in His sovereignty, which means that when God calls, it is powerful and transformative. In the sermon, it is explained that God's calling is not based on human merit or decision but is a sovereign act of grace where the Holy Spirit draws the elect to Christ. This work of regeneration allows believers to respond in faith to the gospel, resulting in their justification and sanctification. Therefore, the assurance of an effectual calling lies in the unchanging nature of God's will and purpose for His chosen ones.