Your mind is an amazing supercomputer. But it’s vulnerable to a “cyber attack.”

On Friday, April 5, Matthew Warren ended his life with a gunshot wound after a lifelong struggle with depression and mental illness. He’s the 27-year-old son of Rick Warren, pastor of Saddleback Church and author of The Purpose-Driven Life.

I could only imagine the shock, guilt, shame and pain his family is feeling right now. This story reminds me of a friend who used to attend our church. He was a nice, quiet young man. Two years ago, he ended his life by jumping out of the window of his hotel room—to the shock and horror of his family and friends.

Matthew Warren was “an incredibly kind, gentle and compassionate young man whose sweet spirit was an encouragement and comfort to many,” a statement from the church said. “Unfortunately, he also suffered from mental illness resulting in deep depression and suicidal thoughts. Despite the best health care available, this was an illness that was never fully controlled, and the emotional pain resulted in his decision to take his life.”

What drove Matthew and my friend to take their lives? Only God knows. And His wisdom, understanding and love are infinitely greater than our own. What the Warren family needs right now is compassion and reassurance.

Our minds are incredibly complex. They’re powerful, yet they’re extremely vulnerable. A barrage of negative and destructive thoughts hit us every single day. Here are three ways we can guard our hearts and minds from a “cyber attack”:

1. Fill your mind with God’s truth.

Truth is the best defense against deception. God’s Word—the Bible—is truth. Jesus Christ said: “You shall know the truth, and the truth shall make you free (John 8:32).” We need to saturate our minds with the truth about the purpose and meaning of life, the truth about our origins and destiny, the truth on how to live, the truth about the purpose of suffering, and the truth of the coming Kingdom of God. Truth is the anchor that keeps us grounded and steadfast through the hard times.

2. Guard the portals to your mind.

Thoughts, both good and bad, enter into our minds through the eyes, ears, and our other sense organs. King David of Israel wrote, “I will set nothing wicked before my eyes,” (Psalm 101:3). These eventually take up residence in the heart. King David’s son, Solomon, wrote, “Keep your heart with all diligence, for out of it spring the issues of life,” (Proverbs 4:23). We need to consciously choose the videos we watch, the music we listen to, the articles we read, and the people we talk to and hang out with.

3. Take conscious control of your thoughts.

Unless we take 100% responsibility for—and conscious control of—what we think about on a moment-by-moment basis, we are leaving our minds open to a “cyber attack” in the form of negative self-talk, suicidal thoughts, depression, etc.

Viktor Frankl, a Holocaust survivor, was robbed of everything he owned and cherished, including his beloved wife. He wrote in his 1946 book Man’s Search for Meaning : “Everything can be taken from a man but one thing: the last of the human freedoms—to choose one’s attitude in any given set of circumstances, to choose one’s own way.”

When everything goes wrong, we can choose to trust God’s unfailing promise:

“Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God; and the peace of God, which surpasses all understanding, will guard your hearts and minds through Christ Jesus” (Philippians 4:6-7).