"Hereafter I will not talk much with you: for the prince of this world comes, and has nothing in me." John 14:30
When trials come, when temptation comes, when people say bad things about us, and so on, it will show us what is inside of us. It will show us where our hearts are. We like to think that we are "perfect", but during these times we will see that our hearts may not be as "pure" as we thought they were.
Confrontation, problems, trials, and difficulties bring out what is inside our hearts so that we can see what is there. Without them we won't know. We will think that all is well. We may think that we are doing all right, while all the while there may be some pride issue, some rebellion, some unforgiveness, some anger, some bitterness, etc. that is hiding in our hearts.
The Bible tells us that our hearts are deceitful and desperately wicked and that we don't know them-- even though we think we do. We don't know the depth of flesh, carnality and wickedness that may be lurking in them. Before you say that a Christian can't have wicked thoughts inside their hearts, let me say this-- at salvation our spirit is born-again; our soul, our heart, our mind has to be renewed and transformed. If there wasn't a chance of wicked thoughts being there, why are we told to "cast them down" and not entertain them?
This is why we must pray that the Lord will create in us a clean heart and renew a right spirit in us. We should pray it daily, but at the same time we should be on the look out for what comes "out of us" when we are facing something that we don't like to deal with. When Jesus was tried, tempted, mocked, confronted by evil men, His heart was pure, the devil could find nothing in Him to use against Him, to accuse Him of, to fault Him with, to gain an avenue and access into His life. The same should be said of us.
Have a great day. Going through trials and problems will show us if there is anything in us that does not need to be in our hearts.
2 Corinthians 10:5