Many commentators, including Benjamin Merkle, Harold Hoehner, Darrell Bock, Constantine Campbell, and others, have viewed φύσει (by nature) in Eph 2:3 as portraying only a genealogical problem of sin. “By nature” refers to a person’s condition from birth, a condition that leads them toward God’s future wrath. However, one can understand φύσις in the Hellenistic world in ways some scholars have quickly dismissed. Ernest Best and Clinton Arnold are two of few scholars to note how this verse potentially contradicts Stoic understandings of φύσις. “By nature” for the Stoic would carry overtones of nature as universe (or God) and the Stoic ideal of forming one’s ethics according to nature to achieve tranquility (Seneca, Epictetus, Zeno, Cleanthes, Chryssipus, et al). This paper examines Eph 2:3 with special attention to the Stoic understandings of φύσις and argues that while Stoics pursued “living according to nature” to achieve a life of tranquility, Paul confronts this idea in Eph 2:3 and reminds primarily Gentile readers that they were dead by nature. Only by the mercy and love of God and union with Christ can one at peace with God and others. To make this point, this paper (1) examines other LXX and NT uses of φύσις, (2) defines the Stoic uses of φύσις and their connection to Stoic ethics, and (3) demonstrates how Eph 2:3 confronts the Stoic ethical admonition to live according to nature in Eph 2:1–5. This study does not supplant most commentators’ views of Eph 2:3, but it supplements them by expanding categories for how ancient readers might hear Eph 2:3. This study also affects how one understands Ephesians 2:11–22 when it later discusses how the cross of Christ achieves true peace for humanity to God and one another as opposed to tranquility achieved by living according to nature.