Several years ago, I purchased a small cactus plant for my office. When I retired, I brought the small plant home with me and continued to care for it. The plant thrived, but it did not get much bigger until the day came that I decided to move the plant to a larger pot. Before long, the cactus plant that was about six inches tall grew to be three times that size with new branches sprouting all over it.
For believers, those of us who have given their hearts to Christ, life before Christ was like that cactus plant. While we were "in the world," we may have thrived in a physically or worldly sense, but we did not experience true growth, spiritual growth. But, when we gave our hearts to Christ and decided to follow Him, God moved us out of the "pot" of the world and replanted us in His kingdom, where we can not only grow but also flourish (Psalm 92:13).
When we are in Christ, when we believe in Him and follow Him, God credits us with righteousness (Romans 4:24). Psalm 92:12 tells us that "the righteous shall flourish like the palm tree" and will "grow like a cedar in Lebanon." Since we are credited with righteousness through Christ, just like my cactus, our spiritual lives will grow exponentially.
Jesus Christ is the vine and, when we are in Christ, we become branches of the vine, able not only to grow but also to flourish and produce fruit that is demonstrated in lives that reflect Christ. But, without Christ, we cannot grow, we cannot produce fruit, for without Him we can do nothing (John 15:5). As long as we remain in Him, we will continue to produce fruit that brings glory to God, even into our old age (Psalm 92:14).