We have many fears. Our physical fears may be heights, water, people, close places or electricity. Some of these are logical fears and some like fear of say paper we would not consider logical. What is our fear as Christians? Maybe we fear loosing close friends or meeting others especially for the first time. Fear or terror in this passage is the fear of the opponent, that is a non/Christian. Maybe we could classify it as fear of Satan and his angels. This fear may be considered to be a logical fear because they may have the potential to do us harm. Possibly we have experienced trouble from them before and wouldn't want to experience any more trouble from them again. In the case of the Philippians the opponent imprisons, tortures and kills Christians. Paul was in prison when he wrote the instructions, "don't fear, you will be severely persecuted and even killed for the faith." Could we handle that kind of persecution? We live, for the most part, a cushy lifestyle. We have big screen TV's and padded recliners to sit in but we take it all for granted. Most of us in this country would be hard pressed to give up the luxuries of home let alone allow ourselves to be persecuted for the faith.
    Heb. 12:4 "You have not yet resisted to the point of shedding blood in your striving against sin;"
The fear of death is the biggest and often the last fear to overcome. We hang onto life even though, as Christians, if we die we will be with God.
    We should not and need not fear the opponent.
    Heb. 13:5-6 "Let your character be free from the love of money, being content with what you have; for He Himself has said, 'I will never desert you, nor will I ever forsake you,' so that we confidently say, 'The Lord is my helper, I will not be afraid, what shall man do to me?"
  I have found that we aren't in control even if we think we are. We can control ourselves but the things around us remain, for the most part, out of our control. We fear loosing money so we accumulate as much as we can not giving heed to the admonition that "The love of money is the root of all evil." It is selfishness. These are the ones described in the parable of the sower, in the third group of seeds.
  Mat. 13:22 "And the one on whom was sown among the thorns, this is the man who hears the word, and the worry of the world, and the deceitfulness of riches choke the word, and it becomes unfruitful." 
God says, "He will never desert us."  Moses instructed the Israelites before he died;
Deut. 31:6 "Be strong and courageous, do not be afraid or tremble at them, for the Lord your God is the one who goes with you. He will not fail you or forsake you."

Joshua was given the same encouragement from God in (Joshua 1:5-6).

Is one of our fears that God might desert us? Friends leave but God won't. Confidence is in the Lord our helper. Man cannot hurt us. Mat. 10:28 "And do not fear those who kill the body, but are unable to kill the soul; but rather fear Him who is able to destroy both soul and body in Hell."
  We heard or sang the song "Sticks and stones will break my bones but names will never hurt me." This was to bolster our moral when we had a person pick on us because of jealousy or just plain