Bible Verses About Steadfastness: In striving for the faith of the gospel

Only let your manner of life be worthy of the gospel of Christ: that, whether I come and see you or be absent, I may hear of your state, that ye stand fast in one spirit, with one soul striving for the faith of the gospel;

Beloved, while I was giving all diligence to write unto you of our common salvation, I was constrained to write unto you exhorting you to contend earnestly for the faith which was once for all delivered unto the saints.