How do you keep your faith in Jesus and God strong...?

The short answer is that you can't. That strength must come from the Lord Himself. When you are bombarded, that is usually a sign that you are doing something positive for the Lord. There is no reason to attack you if you are sitting on the sidelines of spiritual warfare. Keep close to Jesus and your Christian friends. Remember that religion of any sort is a poor substitute for your relationship with the Almighty.