I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in my statutes and be careful to obey my rules” (emphasis added). Water, therefore, is a metaphor for spiritual cleansing, accompanied by God giving people “a new heart, and a new spirit.” Many translations, including the ESV (cited above), capitalize “Spirit” in verse 5, indicating that they think Jesus spoke to Nicodemus about a new birth by the Holy Spirit.