“You can’t be a Christian by yourself.”
Its a saying Sara Miles brings up again and again, and its a saying that has rung true throughout the Church's history. Many have tried. Many burn out with the effort. Unfortunately, its as true as it is wise.
You can't be a Christian by yourself.
I would say, in a very Trinitarian spirit, that you need at least three other people in order to be a Christian.
In order of importance, the first other person you need is God, the Father, the Son, and the Holy Spirit.
And then of course, you need someone else to learn from, learn with, to pick you up, to pick up, to help you when you're feeling discouraged, to remind you of God's love for you... to be on the journey with you.
And... even if you don't want them, you also need someone to challenge you, to help you see God in new ways, to make you get outside of yourself and your ideals and to make things dirty and messy and confusing... that way you go back to that first person: God.