Yes, I understand and that is exactly the reason that you don't tell anyone, because when you do, you loose your benefit from God, by telling other's. I had a friend who was posting information on another site and he came right out and told everyone that he was fasting for forty days. I told him that it would be a good idea to abort this one and reschedule and that because he lost his benefit with God when he did that. Therefore, brownie points, relationship with God, their both the same. Regardless, Jesus said, keep it between you and God. I'm just giving you some brotherly advise here so that you get the benefit from God.
* Be careful not to practice your righteousness in front of others to be seen by them. If you do, you will have no reward from your Father in heaven.
When you give:
"So when you give to the needy, do not announce it with trumpets, as the hypocrites do in the synagogues and on the streets, to be honored by others. Truly I tell you, they have received their reward in full. But when you give to the needy, do not let your left hand know what your right hand is doing, so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you. (Mt.6:2-4)
When you pray:
"And when you pray, do not be like the hypocrites, for they love to pray standing in the synagogues and on the street corners to be seen by others. Truly I tell you, they have received their reward in full. But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you. (Mt.6:5-7)
When you fast:
"When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you. (Mt.6:16-18)
Therefore, the Lord is saying that it doesn't matter what your reason is, don't do it. If you want any kind of benefit/blessing from God, then keep whatever you do between him and you.
I understand the principles that are being given here but would like to add a few things (I just read all 3 pages of posts so hopefully I'm understanding everything in the right context.)
The main principle that God is after in these verses is PRIDE. As always, He is concerned about the motivation of the heart and is basically saying, "Don't use your relationship with me as a way to gain points in the eyes of the people around you."
Tintin is CLEARLY not doing this in his posts. He's new to fasting, and asking for advice, which is a very Godly thing to do: James 1:5--"If any of you lacks wisdom, let him ask God, who gives generously without fault, and it will be given to him."
One of the ways we ask God for help is by seeking Godly counsel from others in the faith: Proverbs 11:14--"Where there is no guidance, people fall, but there is safety in a multitude of counselors."
Tintin is doing the wise thing by asking those around him. He is clearly not "showing off" or trying to "brag" about his spirituality in any way. If anything, he's humbling himself by talking about his struggles and asking for help.
While I do understand the warning about pride, if the person is clearly not being prideful, one must be careful that they're not needlessly hurling arrows of discouragement all "in the name of God." I was in a chatroom once and a young guy, about 20 years old, wanted to talk about his first missions trip. He was so excited and on fire for the Lord, it was just contagious!!
Until some 46-year-old woman told him to be quiet because, as this post pointed out, he was supposedly "losing his credit with God" by talking about it. But this guy wasn't being prideful at all, he was just eager to share what happened. Even Paul said he would not boast foolishly like the world, but that he would put his boasting in Christ, then listed the many hardships (shipwrecks, hunger, sickness, poverty, beatings) he had gone through during his ministry.
I was so upset, because I WANTED to hear this young man's story. But discouraged (and you can see why), he quietly slipped from the room and I never saw him again. I felt so sad about that.
Ironically, I have found that often--not always, but quite often--people who are the most vocal about "keeping your deeds between God and yourself" keep emphasizing this to others because:
1. They're doing a lot for the Lord and supposedly keeping it secret, so if they can't receive any credit, acknowledgement, or encouragement for all their good works, they don't want to see anyone else being encouraged or given positive feedback either.
2. They're not really doing anything for the Lord (except harping on other people and telling them what they should or shouldn't be doing, which they see as doing a great work for God in itself) and when other people talk about their own service, it makes them feel guilty.