Psalms 26

1 This psalm speaks of faith and obedience. People who don't know God can do "good" things, but this will not find them favor with God. God loves those who believe Him. When we love and trust God then we can obey Him and truly do good works. Those who do not believe God may be scornful or violent towards those who do, but God will vindicate those whom He loves.
2 When someone comes to believe and obey God he does not instantly become perfect. The rest of a Christian's life involves growing towards God and turning away from sin. We often can not see our own sins, but God knows all of our sins and will point them out, as we are able to deal with them. The earnestness expressed here does not mean that David is eager to find out more of his sins, but he desires to get closer to God spiritually by getting rid of these sins.
4 Jesus often associated with sinners, but we see two things that would happen. Either a sinner would believe in Him and turn away from sin, or Jesus would harshly chastise those who did not believe and obey God. In a similar manner, the Christian must have contact with non-believers if they are going to have any influence on them, but the Christian should not make "permanent" ties with organizations or people that are deceitful or otherwise wicked. In our weaknesses, most of us tend to be influenced more by evil than by good.
6 When we do what is right, and when we avoid evil, we can approach God in worship without a guilty conscious.
7 It is also easier for us to tell others about God when we are faithful and obedient to Him.
8 This could refer to the original tabernacle, heaven, or even where God lives within us. Today it might extend to church gatherings and small Bible studies. Whatever David had in mind, it is probably safe to say that the Christian should rejoice wherever he might see God at work.
9 God has promised believers that He will rescue them from hell (i.e., eternal separation from Him), but sometimes we need to be reassured when we see how much influence evil has in this world.
12 When one stands for God, his position is firm and stable.