What does Psalm 100:5 mean?

This verse offers three reasons for thanking and praising the Lord (Psalm 100:4). First, He is good. He always does what is best for His children. As the one and only necessary being (Exodus 3:14), He is the very definition of all which is right, true, and righteous.

Second, His love is steadfast. This concept comes from the Hebrew root word he'sed, sometimes rendered as "lovingkindness." This is a loyal, enduring, sacrificial, deep love. A good example of this attitude comes in the love shown by a father for a prodigal son in Jesus' parable in Luke 15:11–32. Although the son had wronged his father, left home, led a corrupt life, and squandered his inheritance, when he returned home, he found the father waiting to welcome him back. Also, the father rejoiced to have his wayward son home again. When Jesus addressed the church at Ephesus, He said the church had abandoned its first love (Revelation 2:4), but He had not abandoned His love for the church. He urged the church to remember the position from which it had fallen, repent, and do the works it had done at first (Revelation 2:5). The Lord's love is everlasting (Jeremiah 31:3).

Third, God's faithfulness extends to all generations. Lamentations 3:23 describes this characteristic of the Lord as "great." He has never broken a promise, left a believer without His care, or failed to do all He said He would do. He has always been reliable and always will be reliable.