From The Imitation of Christ:

When Jesus is near, all is well and nothing seems difficult. When He is absent, all is hard. When Jesus does not speak within, all other comfort is empty, but if He says only a word, it brings great consolation.

Did not Mary Magdalen rise at once from her weeping when Martha said to her: “The Master is come, and calleth for thee”? Happy is the hour when Jesus calls one from tears to joy of spirit.

How dry and hard you are without Jesus! How foolish and vain if you desire anything but Him! Is it not a greater loss than losing the whole world? For what, without Jesus, can the world give you? Life without Him is a relentless hell, but living with Him is a sweet paradise. If Jesus be with you, no enemy can harm you.

He who finds Jesus finds a rare treasure, indeed, a good above every good, whereas he who loses Him loses more than the whole world. The man who lives without Jesus is the poorest of the poor, whereas no one is so rich as the man who lives in His grace.

It is a great art to know how to converse with Jesus, and great wisdom to know how to keep Him. Be humble and peaceful, and Jesus will be with you. Be devout and calm, and He will remain with you. You may quickly drive Him away and lose His grace, if you turn back to the outside world. And, if you drive Him away and lose Him, to whom will you go and whom will you then seek as a friend? You cannot live well without a friend, and if Jesus be not your friend above all else, you will be very sad and desolate. Thus, you are acting foolishly if you trust or rejoice in any other. Choose the opposition of the whole world rather than offend Jesus. Of all those who are dear to you, let Him be your special love. Let all things be loved for the sake of Jesus, but Jesus for His own sake.

Jesus Christ must be loved alone with a special love for He alone, of all friends, is good and faithful. For Him and in Him you must love friends and foes alike, and pray to Him that all may know and love Him.

Never desire special praise or love, for that belongs to God alone Who has no equal. Never wish that anyone’s affection be centered in you, nor let yourself be taken up with the love of anyone, but let Jesus be in you and in every good man. Be pure and free within, unentangled with any creature.

You must bring to God a clean and open heart if you wish to attend and see how sweet the Lord is. Truly you will never attain this happiness unless His grace prepares you and draws you on so that you may forsake all things to be united with Him alone.  When the grace of God comes to a man he can do all things, but when it leaves him he becomes poor and weak, abandoned, as it were, to affliction.

Yet, in this condition he should not become dejected or despair. On the contrary, he should calmly await the will of God and bear whatever befalls him in praise of Jesus Christ, for after winter comes summer, after night, the day, and after the storm, a great calm.

[resources: Imitation of Christ]