Galatians 5:22-24 (ESV):
22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, self-control; against such things there is no law. 24 And those who belong to Christ Jesus have crucified the flesh with its passions and desires.
To what extent can non-Christians develop and manifest the fruit of the Spirit? Is there a theoretical limit that prevents non-Christians from fully developing and manifesting these virtues, that only Christians with access to the power of the Spirit can surpass? What about other religions, such as Buddhism, Hinduism or Islam, that value moral virtues and have their own saints and ethical systems?
Related: How does the power of the Holy Spirit manifest in Christians, as opposed to non-Christians who don't have access to this power?