'Sincerity' in the Bible

Now therefore fear the LORD, and serve him in sincerity and in truth: and put away the gods which your fathers served on the other side of the flood, and in Egypt; and serve ye the LORD.

Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.

For our rejoicing is this, the testimony of our conscience, that in simplicity and godly sincerity, not with fleshly wisdom, but by the grace of God, we have had our conversation in the world, and more abundantly to you-ward.

For we are not as many, which corrupt the word of God: but as of sincerity, but as of God, in the sight of God speak we in Christ.

I speak not by commandment, but by occasion of the forwardness of others, and to prove the sincerity of your love.

Grace be with all them that love our Lord Jesus Christ in sincerity. Amen.

In all things shewing thyself a pattern of good works: in doctrine shewing uncorruptness, gravity, sincerity,