Is faith in Christ something you have forever or do you have to work at it every day to keep it strong?

What do the scriptures say about maintaining your faith in Christ? I know in Mormonism they teach that it's something you have to work at every day and slacking off can lead you to lose your faith and leave the church. But what does the bible say and what does Christianity say about keeping your faith strong? Is it something you have to constantly work at or is it something that once you get you don't lose? For example, in Mormonism you might hear lessons about how you need to attend church, participate and read your scriptures or else you could lose your faith and fall away. Is that strictly a Mormon thing or does Christianity also teach that you have to work at your faith or else you could fall into Atheism?