There is no app to download for any smart phone that proves if a person has been born of the Spirit or is walking in the Spirit. There’s no buzzer, no siren, no spinning light that shows the Spirit’s presence in an individual’s heart. So is it possible to know? Yes.
One signal, not the only one, but one signal of the Spirit’s work is conviction of sin leading to confession. In Ezekiel 36, God promised to send His Spirit and put new spirits within people. One effect of the Spirit’s work is that people will remember their evil ways and their not good deeds and “will loathe [themselves] for [their] iniquities and [their] abominations” (Ezekiel 36:31). In a similar way, Jesus, speaking to His disciples, promised to send the Spirit who, among other things, would convict the world concerning sin (John 16:8).
Without the Spirit there may be misery in sin, but there won’t be conviction of its offensiveness before God. Without the Spirit there won’t be confession of sin to God or others, but rather attempts to hide and rationalize it. Without the Spirit there won’t be acknowledgement of sin, nor any effective impulse to turn from sin. Whole-hearted conviction, open confession, and real repentance are only possible by the Spirit.
He is, after all, the Holy Spirit. His work includes opening our eyes to see sin, stabbing our consciences to loathe sin, and refining our tongues to taste the sweetness of holiness. Our weekly corporate confession depends on the Spirit’s work. If your sin weighs heavily on you and you find relief in confessing it, be thankful for that conviction. That’s a sign that the Spirit has given you life.