All Christians are committed to certain 'credal' beliefs about God, Christ, the Holy Spirit, the Church, etc. But there are other beliefs that actually influence many people more which are not in any creed: beliefs about the sense made by human suffering in relation to the sufferings of Christ, about God's plan for our lives, about how we minister to others, and about the place of sorrow and joy in the Christian life.
Much of what is believed on such matters depends on differences of temperament, and on the style of Christian living encouraged in different churches, whether Protestant or Catholic. Christians can understand each other better by reflecting on such differences and by remembering that being Christian is a way of being human, and therefore allows for diversity of life style and psychological make-up.