Matthew 6:22
"The eye is the lamp of the body. Therefore if your eye is sincere, your whole body will be full of light.
Luke 11:34-36
Your eye is the lamp of the body. When your eye is sincere, your whole body is full of light also. But when it is evil, your body [is] dark also.
2 Corinthians 11:3
But I am afraid lest somehow, as the serpent deceived Eve by his craftiness, your minds may be led astray from the sincerity and the purity of [devotion] to Christ.
Colossians 3:22
Slaves, obey your {human} masters in everything, not {while being watched}, as people pleasers, but with sincerity of heart, fearing the Lord.
Acts 2:46
And every day, devoting themselves [to meeting] with one purpose in the temple [courts] and breaking bread from house [to house], they were eating [their] food with joy and simplicity of heart,
Ephesians 6:5
Slaves, obey your earthly masters with fear and trembling, in the sincerity of your heart, as to Christ,