Testing can bring out our true character. It's in the Bible, II Chronicles 32:31, TLB. "However, when ambassadors arrived from Babylon to find out about the miracle of his being healed, God left him to himself in order to test him and to see what he was really like."
Testing gives us a clear opportunity to grow, with God's help. It's in the Bible, Psalm 11:5, TLB. "He puts the righteous and the wicked to the test; He hates those loving violence."
God invites us to test Him regarding His promise to those who tithe. It's in the Bible, Malachi 3:10, NIV. "Bring the whole tithe into the storehouse, that there may be food in My house. 'Test Me in this', says the Lord Almighty, 'and see if I will not throw open the floodgates of heaven and pour out so much blessing that you will not have room enough for it'."