Dear Ahmad,
As-salam alaykum
Fear is a natural human condition and the balance between irrational and rational fear is one we must understand and deal with appropriately. For example, it would arguably be without wisdom to walk into an angry mob of a particular sectarian mind-set ready for mindless violence and slaughter with a view to attempt to preach to them what they are prepared to kill you for that very reason. One is expected to take sensible precautions and use wisdom in how they strive in the way of God.
For example, even God does not hold a believer responsible if they were to denounce their religion in front of others due to immense fear of the consequences if they did not.
016.106
"Whoever disbelieves in God after his belief, except one who is forced / compelled (akraha) while his heart is content with faith, but he who opens (his) breast to disbelief, then upon them is the wrath of God and for them is a grievous punishment"
Even a believer from the court of Pharaoh (arguably in high rank) hid his faith up till a certain point.
040.028 (part)
"And a believing man from the family of Pharaoh, who had concealed / hid (katama) his faith said "Will you kill a man because he says, 'My Lord is God'?..."
God expects believers to take sensible precautions and make appropriate risk assessments. This is evidenced in another example where even in a state of religious war, where believers were fighting for the sake of God, they were still expected to take sensible precautions during prayer and to split up their congregation where a party could continue to remain vigilant (4.102).
Indeed, this does not mean we shy away at the first opportunity we sense difficulty, fear or danger. We must put our faith in God first, but must act with wisdom and with a view to extract maximum utility in the way of our Lord whether it is to spread the message of truth or otherwise.
For example, the contemporaries of the Prophet were admonished for not striving in the way of God with their property and person (9:81). So whereas they were expected to fight in a particular circumstance, they were still expected to remain vigilant during conflict in general (4.102).
Islam remains a religion of balance and it is oft in the fine choices we make that our soul’s intent is rigorously scrutinised.
100:009
"Does he not know,- when that which is in the graves is scattered"
100:010
And what is in the breasts (deep secrets / thoughts etc) is made apparent?
I hope this clarifies to some extent, God willing.
Joseph