I believe it is true, if we have committed our lives to Christ and have sought to walk with Him every day. And this certainly is God's plan for us, because (as the Bible says) He wants our spiritual lives to grow "in increasing measure" (2 Peter 1:8).
But this doesn't happen automatically, any more than a fruit tree will bear fruit if we never fertilize it or prune it or take care of it. Many Christians, I'm afraid, sincerely commit their lives to Jesus (perhaps when they are young) but then never grow in their faith, and they remain immature and ineffective. They seldom open their Bibles; they go to church only when it's convenient; they only pray if they get in a jam. But the Bible says, "Grow in the grace and knowledge of our Lord and Savior Jesus Christ" (2 Peter 3:18).
I often think of Peter, in the New Testament. He was one of Jesus' closest disciples -- and yet when Jesus was arrested Peter denied he even knew Him. His faith -- at best -- was unstable and weak. But look at him later! He was willing to die for Christ, and his letters as an old man reflect great spiritual maturity.
What made the difference? Simply this: Peter didn't stay still in his faith, but he deliberately grew in his faith as the years passed. Is this happening in your life, as you root your soul in the "soil" of God's Word, and prayer, and fellowship with other believers?