"Catholic." Lutherans tend to be allergic to it, and none more than Lutheran converts from Rome! Yet the word itself which confronts most Lutherans on Trinity Sunday when the Athanasian Creed is confessed is actually defined in that Creed of the Church:
"And the catholic faith is this: that we worship one God in Trinity and Trinity in unity, neither confusing the Persons nor dividing the substance."
By this definition, Lutherans (and all other Trinitarian Christians) are CATHOLICS! And when we confess that Creed we confess that ONLY catholics are saved - for they alone are worshipping that God who alone is the true God, full of forgiveness, life, and salvation. He's the only one who CAN give eternal life.
And with that word comes an obligation - an obligation to set for the faith in its fullness. I am reminded of the remarkable words of Krauth:
"She should lead men, not to the least faith, the least holiness which makes salvation possible, but to the very highest - she should not encourage the religion whose root is a selfish fear of hell, a selfish craving of heaven, but she should plant that religion to which pure truth is dear for its own sake, which longs for the fullest illumination, which desires not the easy road, but the sure one." (Conservative Reformation, p. 191)
Such must be the aim of every Church which would be catholic, which would worship the One God in Three Persons and Three Persons in One God. It must of necessity lead people to the fullness that is in Christ Jesus - a faith not of minimals, but of maximals. A faith whose constitutive center is sharing in the divine life that was born of Mary, nailed to a tree for our sins and raised from the dead for our justification. To be catholic simply means not to settle for anything less than the fullness of Jesus Christ, through whom we give glory to His unoriginate Father in His all-Holy Spirit, now and unto the ages of ages!