If your church does not set a clear business objective, you do not know where you are going, nor do you have no means to measure success. Business objectives can be both long and short term; from sending a group on a mission trip, hosting a conference, raising membership, or even recording a worship CD. Brainstorming with groups and committees can get a long list of items, leadership can prioritize, and your website can certainly help!
Plant your flag
When you create a business objective for your church, you are planting the proverbial flag in the sand. If everyone can see the flag, they can also tell if they are getting closer. The position of the flag may change, but like any traveler; if your destination changes too many times before you can rest at your destination, you will be disillusioned and lose hope. So remember that you can adjust your goals over time (say once a year); but something like once a quarter won’t give projects enough time to show their fruitfulness.
Share your goals
So now that your church has a prioritized list of goals, it is time for the web team to aim the site toward helping accomplish some of them. You may switch out your primary call to action to align with that new goal. Instead of focusing on increasing membership, maybe you can ask for volunteers for an upcoming event, advertise a concert, or promote a guest speaker. Regardless, find a way to draw attention to this special feature on the site.
Courses of action
What form would this call to action be? Obviously a link to another page, but I would recommend some micro-content describing what the action is, along with a large button. I would recommend a button instead of a photograph, because a photo may be perceived as a banner depending on its shape and presentation. Use a unique and/or contrasting color to make the button stand out, and limit the text in the button to one or two action words. Words like "Help Now" "Join Us" are direct and short enough. However, consult a designer to see what their opinion is for your particular situation.
If your church does not have business goals, brainstorm to get several long and short-term goals. Have your leadership prioritize them. Invest some time and money to adjust your website to focus in on your top priorities. Then as an additional action, start measuring your return on investment for those changes!