My Dad and my brothers as served in the Marine Corps. I always wanted to, but the Lord, in His wisdom, saw fit to keep me from passing the physical. Even though I was never able to get into the military, I was impressed about one important focus the Marines had. They always kept in mind what was most important.
The Marines have many different positions, they have many different specialties. If you join the Marines, you can work with computers, fly planes, work as a cook, or many other things. But, when you join the Marines, you are first and foremost a rifleman. Before you go on to specialized training, before you can work in any other field, you must first qualify on the rifle range with a weapon. You are first of all a rifleman.
The same is true in the church. You and I are all parts of One Body, the Body of Christ. We all have different gifts. Some of us are called to preach. Some are gifted to teach, some to sing, some to clean up, some to serve, some to visit, some are called to a specific prayer ministry. Many different tasks the Lord has given us, but first and foremost in our calling is soul-winning. You and I are to be busy leading other people to Christ.