1 Corinthians 16:13

Be on guard; stand firm in your faith (in God, respecting His precepts and keeping your doctrine sound). Act like (mature) men and be courageous; be strong.

Keep the faith and be on guard, not letting the enemy find a way into our lives. If we must guard what we see, hear, and places we go, then we will. The strength of God can keep us when we remain stable and steadfast in the faith. Mark out time for God in the day and keep the relationship strong and the doctrine sound.