It is God’s wish for us to strong in faith (trust in God) and brave in how we faithfully live our lives.  God tells us to feel reassured because God is always near.

我豈沒有吩咐你麼，你當剛強壯膽，不要懼怕，也不要驚惶，因為你無論往那裏去，耶和華你的上帝必與你同在。<約書亞紀1章9節 >