You make countless decisions each day. What to wear. What to eat. How to spend your time. Some decisions are more critical than others. In fact, there seems to be one decision that affects almost every other decision that you make.

The most important decision you’ll make is your community, the people with whom you spend your time.

The biblical author Paul puts it negatively: “Bad company corrupts good character” (1 Corinthians 15:33). If you hang out with the wrong crowd, you’ll inevitably become like them.

When I spend time with people who eat unhealthy, I find myself eating like the group. When I spend time with people who overspend, I find myself buying things I never used to. I’m not blaming others for my actions. But I do believe it’s harder to live with my convictions around people with different values. I might have the best of intentions and even make a bold plan to do the right things. But more often than not, I’ll eventually take on the characteristics of the group I’m in.

The opposite is also true. When I spend time with people I admire, I start acting like them. When I’m around people who read and think critically, I find myself reading more and thinking clearer. When I’m around people who are warm and generous, I start giving more and acting more pleasant.

Do you want to get healthy? Don’t just start a diet. Don’t just start exercising. Join Weight Watchers or a CrossFit gym.

Do you want to be free of addiction? Don’t just try harder. Join Alcoholics Anonymous.

The same principle works with faith. Do you want to be a Christian or a stronger Christian? Don’t just try reading your Bible on your own. Don’t just try to pray more and act more spiritual. Join a group of Christians. Find a church or a small group Bible study. When you spend time with Christians who love Jesus and love people, you’ll eventually start taking on the qualities of that group.

You might have heard people say, “You need to have a personal relationship with Jesus.” At some level that’s true. Nobody can believe in Jesus for somebody else. Everyone has to believe in Jesus for himself or herself.

But that doesn’t mean your faith is an isolated endeavor. When the Holy Spirit calls you to faith, he calls you into the community of faith, into the body of Christ. He knows that you want to continue in your faith if you’re not supported and surrounded by like-minded people. But a community of believers will point out your sin, point you to Jesus, and spur you on to love and good deeds.

This doesn’t mean that you should never be around difficult people who have different values. God has called you to be a light in the world (Matthew 5:14). But if you’re going to be a light, then you need to be energized by a community of believers.

The most important decision that you’ll make today will probably be which community you’ll join. Everything else in your life will most likely follow.