An untested faith is an unreliable faith.
It is easy to say we trust the Lord completely, but when we are put through the heat of trials, that's when the depth of our faith will be revealed. David knew about the refining and revealing nature of trials. He gives two main declarations:
1) Trust only in the Lord.
Three times in this Psalm, David uses the word "only" in reference to God.
Psalm 62:2 "He only is my rock and my salvation; he is my defence; I shall not be greatly moved."
Psalm 62:5-6 "My soul, wait thou only upon God; for my expectation is from him. He only is my rock and my salvation: he is my defence; I shall not be moved."
Wait ONLY upon God. He ONLY is my rock.
We declare we completely trust Him, but when trials come, what do our actions, attitudes, and words say we trust? David said there was a temptation to trust in other things.
Psalm 62:10 "Trust not in oppression, and become not vain in robbery: if riches increase, set not your heart upon them."
Oppression: strength, "strong-arming" your problems, control
When a trial comes along, do you depend on inner strength? Fortitude? Positive attitude and nature? Talents? Skills? Don't trust in how you can control (oppress) the situation. David was tempted in this area. As king, he had access to a great army. He had amazing resources at his disposal, and yet he chose to trust in his God.
Robbery: Taking something that isn't yours.
When a trial comes your way, do you resort to things that are off-limits to Christians? Do you scheme and plot? Do you try to use your own logic to solve the problem instead of following the lead of the Spirit and God's Word? Sometimes God has a plan that doesn't make sense logically. He sometimes tells us "no" to things that aren't necessarily sin... they just aren't His will for us. When we try to go down a path that God says no to, it is like robbery. That isn't our path to take.
Riches: Financial security, assets, and resources. House, job, bank account, car, health, etc.
When trials come, is your confidence in your resources? Do you think your job is secure? Do you think your home is safe? If God allows these things to be taken away, will your faith be shaken? Will you be consumed with depression? Will you still serve Him if your health is taken from you?
2) Trust in Him at all times... good and bad!
Psalm 62:8 "Trust in him at all times; ye people, pour out your heart before him: God is a refuge for us. Selah."
It is so easy to praise Him and trust Him when things go smoothly, but the real test begins when things are not easy or comfortable. David says to trust Him at all times. He says to learn to make calling out to Him your first resort and your battle plan for when trials come instead of relying on your strength, logic, or financial stability.
What do you do when trials come? When the next trial hits, take note of what you default to in order to solve the problem.