David prays a very admirable prayer in Psalm 139:23-24 saying, "Search me, O God, and know my heart; Try me and know my anxious thoughts; And see if there be any hurtful way in me, And lead me in the everlasting way."  David is quick to understand and admit that he is prone (as we all are) to hidden sins (see Psalm 19:12), errors of heart of which we are not yet aware.  Once we become aware of them, we need to deal with them, and it is David who sets an example of being proactive in this process.  Rather than waiting for sin to happen and the consequences to result, David asks God to show him where his faults might lie.  If he can be made aware of them before they hurt him or others, why wouldn't he prefer to be changed ahead of time?  This is exactly what a person with a tender heart toward God ought to do.  He ought to ask God to search his heart so that he can be made aware of anything that needs to be dealt with.  The wonderful thing is that David has already acknowledged in verse one of this same chapter that God has already searched him and known him.  God already knows the errors in David's heart and makeup.  It is once David realizes just how much God knows about him and how much God thinks about him that David comes to welcome God's searching out of his heart so that he can benefit from the knowledge which God possesses about him.  It is a privilege as a child of God to have the mind of Christ (1 Corinthians 2:16), part of which, is to be made aware of our weaknesses and sin.
 

God has given us as the body of Christ a specific time to be introspective, though His desire is that we should deal with sin as quickly as possible all the time.  The Lord's Supper is a fixed time to mediate upon the work of Christ on the cross, a large part of which involves doing what David did in asking God to search and know his heart.  When we partake in communion, we ought to ask God to try us and see if there are any wicked ways within us.  If there are, we ought not to partake until we repent or make an issue right with a brother or sister whom we might have sinned against.  This is the sanctifying part of this ordinance instituted by Christ.  It is a time to reflect upon the blood of Christ shed for us and the body of Christ broken for us such that we remember who we are in Christ to the extent that we want to honor Him fully with our lives.  Paul is adamant in 1 Corinthians 11:29 that we be introspective about sin and "judge the body rightly."  Verses 28-30 say the following: "But a man must examine himself, and in so doing he is to eat of the bread and drink of the cup. For he who eats and drinks, eats and drinks judgment to himself if he does not judge the body rightly.  For this reason many among you are weak and sick, and a number sleep."  When we let sin go unchecked in our lives, it can bring decay to our bodies (Psalm 32:3), and it certainly brings decay to our souls (Galatians 5:9).  God doesn't take lightly to blatant blasphemy and hypocrisy during such a solemn occasion.
 

The highest honor we can give Christ Who died for us is to die to self and live for Him.  The greatest insult we can cast upon Him is to refuse the grace and sanctifying power which He died so that we could freely receive.  When we hide sin in our hearts, we insult Christ by refusing His gift and blaspheming His redemptive work.  It is not that we lose our salvation when we harden our hearts, but we certainly grieve the heart of God greatly.  It delights God's heart when we purify ourselves as He is pure during the time of communion or at any other time (1 John 3:3).  May we not forget the importance of introspection and self-examination when taking of the Lord's Table.

One of the best ways to keep walking in the straight and narrow way is to be regularly introspective.  This involves being sensitive to the Holy Spirit's conviction, being humble in reading the Word, and praying proactively for God to reveal character flaws that need to be rectified and sanctified.  May we take it upon ourselves to pray as David did that God would search us and know us so that we could be sanctified and changed.