1 Chronicles 29:17 (Berean Study Bible)
All these things I have given willingly and with an honest intent.
Why are we serving God? People respond differently to that question. Some may say because it's my duty, or beacuse I enjoy doing it, or I want to serve humanity and so on. These may all be logical but not truly honest reasons. The only reason we should serve God is because it pleases and glorifies Him.