How do we know the Holy Spirit has come upon us?

The evidence of the Holy Spirit's presence in a believer's life is manifest through faith in Jesus Christ. When the Spirit works in a person's heart, He causes them to grasp the reality of Christ's atoning sacrifice and the sufficiency of His righteousness for salvation. This understanding creates a focus on Jesus alone as the hope of salvation, confirming that the Spirit has indeed come and transformed the heart. True faith will lead to a conviction of sin, an acknowledgment of Christ's work, and a response of worship and reliance on God's promises.