Another reason is urged in verses 16 to 18.  It displays the true character of Christianity, and so reflects honour on the doer.  ’Your good’ is an expression for the whole sum of the blessings obtained by becoming Christians, and is closely connected with what is here meant by the ‘kingdom of God.’  That latter phrase seems here to be substantially equivalent to the inward condition in which they are who have submitted to the dominion of the will of God.  It is ’the kingdom within us’ which is ’righteousness, peace, and joy in the Holy Ghost.’  What have you won by your Christianity? the Apostle in effect says, Do you think that its purpose is mainly to give you greater licence in regard to these matters in question?  If the most obvious thing in your conduct is your ‘eating and drinking,’ your whole Christian standing will be misconceived, and men will fancy that your religion permits laxity of life.  But if, on the other hand, you show that you are Christ’s servants by righteousness, peace, and joy, you will be pleasing to God, and men will recognise that your religion is from Him, and that you are consistent professors of it.

Modern liberal-minded brethren can easily translate all this for to-day’s use.  Take care that you do not give the impression that your Christianity has its main operation in permitting you to do what your weaker brethren have scruples about.  If you do not yield to them, but flaunt your liberty in their and the world’s faces, your advanced enlightenment will be taken by rough-and-ready observers as mainly cherished because it procures you these immunities.  Show by your life that you have the true spiritual gifts.  Think more about them than about your ‘breadth,’ and superiority to ‘narrow prejudices.’  Realise the purpose of the Gospel as concerns your own moral perfecting, and the questions in hand will fall into their right place.

In verses 19 and 20 two more reasons are given for restricting liberty in deference to others’ scruples.  Such conduct contributes to peace.  If truth is imperilled, or Christ’s name in danger of being tarnished, counsels of peace are counsels of treachery; but there are not many things worth buying at the price of Christian concord.  Such conduct tends to build up our own and others’ Christian character.  Concessions to the ‘weak’ may help them to become strong, but flying in the face of their scruples is sure to hurt them, in one way or another.

In verse 15, the case was supposed of a brother’s being grieved by what he felt to be laxity.  That case corresponded to the stumbling-block of verse 13.  A worse result seems contemplated in verse 20,—­that of the weak brother, still believing that laxity was wrong, and yet being tempted by the example of the stronger to indulge in it.  In that event, the responsibility of overthrowing what God had built lies at the door of the tempter.  The metaphor of ‘overthrowing’ is suggested by the previous one of ‘edifying.’  Christian duty is mutual building up of character; inconsiderate exercise of ‘liberty’ may lead to pulling down, by inducing to imitation which conscience condemns.