What evidence do we have that God's promises are fulfilled?

Evidence of God's promise fulfillment is abundant, both in scripture and in the lives of believers today. The events of Acts 2 provide clear evidence of the fulfillment of the Holy Spirit's promise, as the apostles witnessed and experienced the power of God in a radical way. Additionally, Peter's references to Old Testament prophecies during his sermon underscore how past promises have been realized in the person of Christ. Moreover, in the lives of contemporary Christians, personal testimonies become profound evidence as individuals reflect on instances where they have witnessed God answering prayers, providing guidance, or strengthening them according to His word, ever affirming that He does not fail to keep His commitments.