"Serve Him in sincerity and truth" (Jos 24:14). Sincerity and truth are the weights that keep the soul in balance.
Sincerity is the ring of the coin which tells out its genuineness; the straight line of rectitude, and the test of fidelity.
The term rendered "sincerity" is translated "perfect" in Gen 17:1; "without blemish" in Lev 1:3; "full" in Lev 25:30; "upright" in Psa 37:18; "undefiled" in Psa 119:1; "sound" in Psa 119:80; and "whole" in Pro 1:12. We should serve the Lord with—
1. Sincerity of purpose (Col 3:24).
2. Perfectness of walk (1Th 1:9).
3. Unblemishedness of life (Act 26:7).
4. Thoroughness (Rom 12:1).
5. Uprightness of heart (Rom 12:2).
6. Undefiled conduct (Luk 1:74).
7. Soundness of motive (Rom 7:6).
8. Wholeness of being (Hbr 12:28).