'Fidelity' in the Bible

For, by the practical proof of it which you exhibit in this service, you cause God to be extolled for your fidelity to your professed adherence to the Good News of the Christ, and for the liberality of your contributions for them and for all who are in need,

But I am afraid that, as the serpent in his craftiness deceived Eve, so your minds may be led astray from their single-heartedness and their fidelity to Christ.