The Imitation of Christ
Book two - Thoughts helpful in the life of the Soul
2.06 Of the joy of a good conscience
THE glory of a good man is the testimony of a good conscience. Therefore, keep your conscience good and you will always enjoy happiness, for a good conscience can bear a great deal and can bring joy even in the midst of adversity. But an evil conscience is ever restive and fearful.
Sweet shall be your rest if your heart does not reproach you.
Do not rejoice unless you have done well. Sinners never experience true interior joy or peace, for "there is no peace to the wicked," says the Lord. Even if they say: "We are at peace, no evil shall befall us and no one dares to hurt us," do not believe them; for the wrath of God will arise quickly, and their deeds will be brought to naught and their thoughts will perish.
To glory in adversity is not hard for the man who loves, for this is to glory in the cross of the Lord. But the glory given or received of men is short lived, and the glory of the world is ever companioned by sorrow. The glory of the good, however, is in their conscience and not in the lips of men, for the joy of the just is from God and in God, and their gladness is founded on truth.
The man who longs for the true, eternal glory does not care for that of time; and he who seeks passing fame or does not in his heart despise it, undoubtedly cares little for the glory of heaven.
He who minds neither praise nor blame possesses great peace of heart and, if his conscience is good, he will easily be contented and at peace.
Praise adds nothing to your holiness, nor does blame take anything from it. You are what you are, and you cannot be said to be better than you are in God's sight. If you consider well what you are within, you will not care what men say about you. They look to appearances but God looks to the heart. They consider the deed but God weighs the motive.
It is characteristic of a humble soul always to do good and to think little of itself. It is a mark of great purity and deep faith to look for no consolation in created things. The man who desires no justification from without has clearly entrusted himself to God: "For not he who commendeth himself is approved," says St. Paul, "but he whom God commendeth."
To walk with God interiorly, to be free from any external affection -- this is the state of the inward man. --  Isa. 48:22.  2 Cor. 10:18.