The following is an excerpt from the Albert Barnes Commentary which is a part of my SwordSearcher bible study software (www.swordsearcher.com).  In this particular portion he is providing a verse-by-verse overview of 2Corinthians 4.  I am providing this for our provocation.  As Christians we have been called to be ambassadors for Christ, to be always ready to give a reason for the hope we have in Christ.  This commentary is a very practical and powerful exhortation to this end.  May God bless it to your heart according to His will.

Albert Barnes Commentary

In order to animate us in the work to which God has called us; to encourage us in our trials; and to prompt us to a faithful discharge of our duties, especially those who like Paul are called to preach the gospel, we should have, like him, the following views and feelings--views and feelings adapted to sustain us in all our trials, and to uphold us in all the conflicts of life:

1st.  A firm and unwavering belief of the truth of the religion which we profess, and of the truth which we make known to others, 2Cor 4:12. No man can preach successfully, and no man can do much good, whose mind is vacillating and hesitating; who is filled with doubts, and who goes timidly to work or who declares that of which he has no practical acquaintance, and no deep-felt conviction, and who knows not whereof he affirms. A man to do good must have a faith which never wavers; a conviction of truth which is constant; a belief settled like the everlasting hills, which nothing can shake or overturn. With such a conviction of the truth of Christianity, and of the great doctrines which it inculcates, he cannot but speak of it, and make known his convictions. He that believes that men are in fact in danger of hell, WILL tell them of it; he that believes there is an awful bar of judgment, will tell them of it; he that believes that the Son of God became incarnate and died for men, will tell them of it; he that believes that there is a heaven, will invite them to it. And one reason why professing Christians are so reluctant to speak of these things is, that they have no very settled and definite conviction of their truth, and no correct view of their relative importance.

2nd.  We should have a firm assurance that God has raised up the Lord Jesus, and that we also shall be raised from the dead, 2Cor 4:14. The hope and expectation of the resurrection of the dead was one of the sustaining principles which upheld Paul in his labours, and to attain to this was one of the grand objects of his life, Acts 23:6; Phil 3:11. Under the influence of this hope and expectation, he was willing to encounter any danger, and to endure any trial. The prospect of being raised up to eternal life and glory was all that was needful to make trials welcome, and to uphold him in the midst of privations and toils. And so we, if we are assured of this great truth, shall welcome trial also, and shall be able to endure afflictions and persecutions. They will soon be ended; and the eternal glory in the morning of the resurrection shall be more than a compensation for all that we shall endure in this life.

3rd.  We should have a sincere desire to promote the glory of God, and to bring as many as possible to join in his praise, and to celebrate his saving mercy, 2Cor 4:15. It was this which sustained and animated Paul; and a man who has this as the leading object of his life, and his great purpose and aim, will be willing to endure much trial, to suffer much persecution, and to encounter many dangers. No object is so noble as that of endeavouring to promote the Divine glory; and he who is influenced by that, will care little how many sufferings he is called to endure in this life.

Christians should have such a belief of the truth of their religion as to be willing to speak of it at all times, and in all places, 2Cor 4:13. If we have such a belief we shall be willing to speak of it. We cannot help it. We shall so see its value, and so love it, and our hearts will be so full of it, and we shall see so much the danger of our fellow-men, that we shall be instinctively prompted to go to them and warn them of their danger, and tell them of the glories of the Redeemer.