You are what you think. Thoughts are important. If your thoughts are wrong, your life is wrong. If your thoughts are right, your life is right, even right with God. The way to think right is to think God's thoughts. His thoughts are found in the Bible. How precious also are Your thoughts to me, O God! How great is the sum of them (Psalm 139:17).
Think God's thoughts in the Bible. Meditate upon the words. Meditation is even repeating the words out loud. It is feeding upon God's words. When you meditate upon God's thoughts, you begin to think like God. Faith in God includes thinking like God. His thoughts for you give faith. So then faith comes by hearing, and hearing by the word of God (Romans 10:17).
Think God's thoughts for victory in spiritual warfare. The battlefield is your mind. The world's thoughts compete for your attention. God's thoughts give victory in the battle for your mind. God's thoughts and words renew your mind. Be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God (Romans 12:2).
Think God's thoughts to produce good fruit. His word is like seed planted in your mind. You cultivate the mind with meditation upon the word of God. It grows and produces good fruit, even the fruit of the Spirit. Your mind is changed. That's called repentance. Your life is changed. That comes from the word of grace. Your faith grows to trust God in all things.