Sometimes doing the wrong thing for the right reason can be right in God's eyes. But that's not really what you're describing here. You're talking about service to mammon while slipping a payment to God here and there to make it all seem ok.
Here's a real-world example to show why this kind of argument just doesn't work. Revelation 13 talks about a Mark which will be used to control all buying and selling. Whatever ideas you may have about when the rapture will happen or what the Mark will look like, the fact is that its purpose will be to control all buying and selling. If you want to take care of your family, if you want to make your car payments, if you want to help that guy in prison, if you want to pay your taxes, if you want to put food on the table and pay all your bills, you will have to take the Mark.
According to the arguments you guys have been using so far, it should be okay for you to take the Mark because it's not like you will love it; you will only use it to feed your family and pay the bills. After all, if you don't work you shouldn't eat and a man who doesn't take care of his family is worse than an infidel, so you've got good reason to take the Mark. God will understand that you're just trying to be a good steward with the blessings he wants to give you and because he knows your heart, he won't blame you for just trying to take care of your family. You may even become a good witness to others who have taken the Mark but who use it selfishly. You can show them how to use it for love. If you don't take the Mark yourself, you wouldn't be able to reach them. They'd think you don't understand or that you think you're better than they are.
You can't have it both ways. If you're working for the purpose of getting something for your work, then you can't say that work is being done for love. Donations and sharing are fantastic ways to express the values of the Kingdom of Heaven, but if you decide that you will only work IF you get payment (of whatever kind) in return, then you'v gone beyond sharing into materialism.
Insisting that your service to mammon is really love because you will use a portion of it to help your family or a stranger in jail is self deception. At least be honest about what it is; if you didn't get paid you wouldn't do the work meaning the purpose of the work is to get money. You may be able to convince yourself that your arguments about it really being work for love are legit, but remember that you will stand before the inventor of all wisdom and knowledge and I doubt he will be fooled by it. It is not enough that you feel convinced; you must be able to convince him and according to the teachings of Jesus you're likely to be one of those people who said, "Lord, I've done many works in your name" and he will say, "I never knew you". The people in this example called him Lord and claimed to do works in his name. They believed they were saved. They had convinced themselves that the part-time help they offered to others here and there was good enough, while the bulk of their time was spent "working iniquity" which sounds pretty bad, but iniquity can be as simple as performing a normal, routine job for the wrong reason.
This argument appears only a few verses after his instructions about living by faith, where he says we cannot work for both God and money at the same time, and then launches into comments telling us to consider the birds and flowers because they do not work for money and yet God takes care of them. He says all the heathens of the world chase after money, but that we should not be like them. Instead, we should seek the kingdom of Heaven, first.
Are the luxury car and designer jeans really what you think God wants you to spend your time and resources on after you've done the bare minimum of taking care of your own kid?
No one is saying that sharing is bad. It's actually a good thing to share with others. Are you familiar with the story of Samuel and King Saul who was commanded to destroy the Amalekites in toto? Saul did attack them and destroyed most of them, but brought the king, the best treasures, and the best animals back with him as a sacrifice for God. When Samuel heard about it he challenged Saul who tried to explain that he was just trying to do a good thing for God and Samuel told him, in essence, to shut up. He told him it is better to obey than to sacrifice. After that, God removed his favor from Saul. He was not impressed with Saul's explanations about sacrifice. He saw right through it because he's not stupid.
What is the point of trying to help others if we are not willing to do it the way God wants us to do it? When you use these examples of the good you've done to justify your choices, it's like you're saying, "yes, Jesus did say that we cannot work for God and money at the same time, BUT Jesus didn't understand that we really can work for both at the same time because money is just a tool and as long as you don't love the money, and as long as you use a bit of it to help people here and there, then it's all good".
Here on this forum, and probably in your church, you're surrounded by people who will agree with you, because they all use the same arguments. You may feel emboldened by this support. You probably feel it is confirmation that you really are on the right track. I understand the sense of comfort that agreement with others can bring.
But when you stand before God you will do so as an individual. God will ask you what you did with the teachings of his son. He will not care about what Paul did or said. He will not care about what your pastors told you. He will not care about what other people on this forum, what your wife, or your kids said to you. And when you try to explain to him that you spent your life in service to mammon because money makes the world go round he will not be impressed.
You are taking a huge risk with these flimsy arguments. The teachings of Jesus will change us. They will cause us to confront our fears. They will cause us to confront our greed. They will cause us to reevaluate everything. Jesus likened obedience to falling on a rock and being broken. It's not a particularly pleasant analogy, but it is an apt description of the kind of feelings and discomfort we feel when we're forced to look at ourselves in the light of Jesus' standards.
