And verses 22-23 tell some of the ways to contend for the faith. The best thing we can do to become a church that is effective in contending for the faith is to become a church well built on the faith. Build yourselves up on your most holy faith. There is so much wonderful truth about God to learn. And the best defence of the faith is to know it and love it.
Prayer is an indispensable part of contending for the faith.
Pray in the Holy Spirit. Unless we seek the mind of the Holy Spirit in prayer we will not grow in our grasp of the faith and we will be weak contenders. At least two things are evident here. Contending for the faith is never merely an academic exercise. It is never merely mental.