Psalm 20 v 7 - Some put their trust in chariots and some in horses, but we will call only on the name of the Lord our God
There is an advert for a Christian television channel that asks this question of the ordinary person on the street " In what or in whom do you put your trust?" Various answers are given, for example, "Myself", " my family", "Manchester United"... (!) The problem with putting your trust in anything other than God is that you will inevitably be let down. Human beings, (and especially football teams) are not infallible; they disappoint, they make mistakes, even when they intend to do the opposite. Trusting in human beings is like building your house on sand; without sure foundations it will crumble when storms come. The writer of the Psalm above knew that trusting in anything else apart from God was futile.
God asks us to trust in Him as a child would in a good parent. This kind of trust does not come without questions and doubts, and that's OK with God, because in Jesus, He knows what it is like to be us. He simply asks us to trust Him, even though we sometimes cannot see the path ahead. Like a son taking his father's hand through a dark forest, he trusts that dad will bring Him out on the other side into the light - and he does. So it is with trusting God. He will never let you down.