The sea squirt is a strange creature. Found attached to rocks and shells, it looks like a soft plastic tube waving with the current. Drawing its nutrients from the passing water, it lives a passive life far removed from its once active youth.

The sea squirt starts life as a tadpole with a primitive spinal cord and brain that helps it find food and avoid harm. As a juvenile it spends its days exploring the ocean, but something happens when it reaches adulthood. Settling on its rock, it stops exploring and growing. In a macabre twist, it digests its own brain.

Spineless, thoughtless, flowing passively with the current. The apostle Peter encourages us not to follow the sea squirt’s fate. Since maturity for us means taking on God’s nature (2 Peter 1:4), you and I are called to grow—grow mentally in our knowledge of Christ (3:18); spiritually in traits like goodness, perseverance, and self-control (1:5–7); and practically by exploring new ways to love, offer hospitality, and serve others through our gifts (1 Peter 4:7–11). Such growth, Peter says, will stop us living “ineffective and unproductive” lives (2 Peter 1:8).

This calling to grow is as vital for the 70-year-old as it is for the teenager. God’s nature is as vast as the ocean. We’ve barely swum a few feet. Explore His unending character, take new spiritual adventures. Study, serve, take risks. Grow.