In my understanding, Christianity is primarily about TWO RELATIONSHIPS:
1 – OF HUMAN BEINGS WITH GOD, based on a personal relationship by each of us with Christ (in some cases mediated by the clergy) and practiced by prayer.
2 – OF HUMAN BEINGS WITH EACH OTHER, practiced by following Christ’s and the church’s teachings that pertain to human relationships (the Golden Rule, and others). You will find Christ’s teachings in the New Testament.
IF we are able to establish and cultivate good relationships with God and with each other on Earth, we are promised that our eternal souls will enjoy eternal life with God in heaven. Otherwise, our souls may be forever barred from communing with God in heaven.
THE COURAGE OF FAITH
Faith, by definition, can only exist under two conditions: in the absence of physical evidence that God exists and in the presence of doubt. If we had direct evidence of God’s existence, we wouldn’t need “faith” but simply the acceptance of reality.
Regarding doubt, it works in a similar way to courage, which can only exist in the presence of fear. Just as courage can overcome (and coexist with) fear, faith can overcome (and coexist with) doubt.
The application of the Christian faith, i.e., when faith translates into behavior, is more problematic for human beings. We often fall short, make bad decisions, and contradict our beliefs. Reconciling with God is much easier since the advent of Christ, who brought redemption and salvation for all.
Believe it. Or not.