Jude 1: 3, 4 Beloved, while I was very diligent to write to you concerning our common salvation, I found it necessary to write to you exhorting you to contend earnestly for the faith which was once for all delivered to the saints.
In this brief book of the New Testament we’re admonished to “contend earnestly for the faith”, which means to battle, literally go to war for.
The context for which we’re to battle on behalf of the faith in large part deals with denial of the deity of Jesus. Denial of the deity of Christ is foundational to heretical teaching and aberrations of faith. These are appointed for destruction if there is not repentance.
We might refer to the kind of faith these “certain men” had as “presumptive grace faith”. They presumed God’s grace would cover up their “lewdness”, which refers to sensuality, because they had been “born again.”
Again remember grace is the empowerment to live victoriously over work of the flesh.
At a personal level, we battle for the faith by moment by moment yielding to the Lordship of Jesus. Contend for the faith in your life!