One of the reasons for this, I believe, is that as we obey God s word and discipline ourselves to do his will, we feel good about ourselves - after all, this is what God created us to be. This translates into being confident in all our endeavors. Confidence breeds success. Also, we have a helper, the Holy Spirit, who, when we fail, will lead us back toward the road to victory. All these promises are made to the one who mediates on God and his word.
Meditation is a result of discipline.
We read the Bible, we pray, and we meditate. This means we must be willing to spend some quiet time alone with God. Meditation occurs when we are alone with God, and meditation can continue to occur throughout our day as we consider all that God is teaching us. As a child raised in the church or as a new believer, we become firmly planted as we become grounded in the word by reading and learning the Bible. As we mature, we begin to bear fruit.