"We have shown good battling qualities and that is one thing we have had to bring to the game - there are that many good footballers here and if we can battle as well we will be fine," he says.
"We feel it has been coming because we have had disappointments all season, but even through them we have been working really hard, and in the last few games we have had a really settled defence with the same players playing every week.
"We thought we should have won against Sunderland and against Aston Villa and Saturday was a good performance, but the important thing to do now is build on it."
Christian admits he has been frustrated by not picking up more points recently, and adds: "It gets you a bit down but we've kept training really hard, and I said to the boys after the game at Old Trafford that it just shows how hard the team works and the fitness is good, because basically we are using the same players in almost every game, and we've just come through three in a week.
"We were playing against a Man United team who have the luxury of being able to chop and change a little bit and bring fresh guys in, but we played Saturday-Wednesday-Saturday and we were still bombing around at the end.
"We are getting the benefits of training so hard.
"We feel we should have got more points in the bag, there is no doubt about that, but we haven't and we have got to deal with that."
Ever-present Christian insists the work ethic must be maintained - and also thinks continuity is vital.
"We have got to keep working hard in every game," he says, "the front guys were closing down on Saturday, the midfield were doing a great job for us, and David James was fantastic behind us.
"We are trying to be really together and that is the message we are trying to give out - it is a really close bunch.
"Tomas Repka is a tremendous player and obviously with every game you play the understanding is only going to get better and better, so we have just got to try and keep it going.
"West Ham is a great place to play and the lads are so down to earth which is what you really want - players that want to work hard."
Christian says he will not get too carried away with the win at Old Trafford, and agrees with Glenn Roeder who uses the phrase 'one swallow doesn't make a summer.'
"I completely agree with him there," he says, "it is one result, but what is pleasing from my point of view is that the performances have been much more solid and the team has looked like we have been playing together for a while now.
"It is enjoyable, but you try and treat every game like it was Manchester United and it was no different to Sunderland the week before when we were bombing about trying to win the ball.
"Sometimes you can do that and not get a result and it is easy to get the head down, but the boys haven't, even when we conceded in the first minute against Aston Villa."
Of course, it doesn't get any easier with the visit of Arsenal this Saturday, and he says: "We have got a really tough programme coming up but we go into that game with some confidence.
"This weekend is a really difficult game because Arsenal are really flying and they are as good as anyone in Europe just now.
"Their strikers the other night made the world class defenders of Juventus look so ordinary.
"But at least we can go into the game with confidence and we can enjoy it.
"I never get too up or too down with it - I just think it is really important after a game to start focusing on the next one.
"We have just got to keep it going."