What we think matters. When asked by a lawyer what the greatest commandment is, quoting from Deuteronomy Jesus says to love the Lord your God with all your heart, with all your soul, with all your mind, and with all your strength. We are to love God with every part of us, and that includes our minds. In that same response to the lawyer Jesus also says to love your neighbor as yourself. We cannot exercise love to our neighbor when we harbor angry or sinful thoughts against them. Our mind is a battleground, and what we think can either guard us against Satan’s attacks or not.
There are different types of thoughts that Scripture warns us about: anxious, worried thoughts (Philippians 4:2-9), angry thoughts and adulterous thoughts (Colossians 3:1-17. However, we are also given instruction in how to overcome these wrong thoughts. We can guard our minds by carefully choosing what we watch and listen to. We can clear our minds of once legitimate thoughts that turn into bitterness or resentment. Finally, we can fill our minds with good things like God’s truth (Psalm 119:9, Colossians 3). We also need the power of the Holy Spirit to work in us to guard and clear our minds of wrong thoughts and fill it with Truth (Romans 8).