Why Does the Lord Test Us?

Is it to find out what we're made of?
No; He knows perfectly.
He wants us to know what we're made of.

Why?

So that we will not trust in ourselves but in Him alone. He does not want our faith to be in man but in God.

He wants to reveal to us our shortcomings so that we will present ourselves to Him to be made perfect. And Jesus has already made us perfect. As long as our faith is in Him, we are made holy before God. When we trust in Jesus, our righteousness is the righteousness of Christ Himself; we are accepted in the Beloved.

If we depart from His ways and trust in our flesh or trust in other men to save us from God's wrath, then we are left un-covered and become vulnerable to the attacks of the enemy. The enemy can only strike us where we are not in submission to God and where we do not wear the armor of God. So when we are tested, the vanity of our flesh is revealed.

Trusting in man, trusting in Egypt, trusting in chariots, trusting in leaders, trusting in religious ceremonies and rituals, praying as the heathen do, who think God will hear them for their many words. These are all forms of idolotry, and God means to drive these things from our hearts so that He will be our only God, and we will be His people. He wants us to be intimate with Him, to know His love and His peace, and in order to do that, we must have all idols driven from our hearts. Our sin must be revealed before we are able to repent and confess it to Him. The Lord wants an open communion with us; He wants us to see Him and to know Him and to walk with Him. He wants to bless us with His presence and His glory and to provide for us lavishly and abundantly.

Hebrews 4:13
And there is no creature hidden from His sight, but all things are naked and open to the eyes of Him to whom we must give account.

John 4:23-24
But the hour is coming, and now is, when the true worshipers will worship the Father in spirit and truth; for the Father is seeking such to worship Him.
God is Spirit, and those who worship Him must worship in spirit and truth.

Psalm 103

11 For as the heavens are high above the earth,
So great is His mercy toward those who fear Him;
12 As far as the east is from the west,
So far has He removed our transgressions from us.
13 As a father pities his children,
So the Lord pities those who fear Him.
14 For He knows our frame;
He remembers that we are dust.

God already knows us and loves us. He wants us to know Him as He knows us. It is His by mercy that He brings us testing!

1 Corinthians 13:11-12
When I was a child, I spoke as a child, I understood as a child, I thought as a child; but when I became a man, I put away childish things.
For now we see in a mirror, dimly, but then face to face. Now I know in part, but then I shall know just as I also am known.

2 Corinthians 3:18
But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as by the Spirit of the Lord.