26:1-3 David was not claiming to be sinless—that is impossible for any human being to achieve. Instead, he was pleading with God to clear his name of the false charges made against him by his enemies. We also can ask God to examine us, trusting him to forgive our sins and clear our record according to his mercy.
26:4, 5 Should we stay away from unbelievers? No. Although Christians should avoid some places, Jesus demonstrated that we must go among unbelievers to help them. There is a difference, however, between being with unbelievers and being one of them. Acting like unbelievers harms our witness for God. Ask yourself about the people you enjoy: If you are with them often, will you become less obedient to God in outlook or action? If the answer is yes, carefully monitor how you spend your time with these people and their effect on you.
26:8 God’s house in this verse refers to either the Tabernacle in Gibeon (the one constructed in the days of Moses; see Exodus 40:35) or the temporary dwelling David built to house the Ark of the Covenant (2 Samuel 6:17). David exclaimed how he loved to worship God at this place. Do you love to worship?
26:12 Too often we complain about our problems to anyone who will listen and we praise God only in private. Instead, we ought to complain privately and praise God publicly.