It's one of Jesus' many shocking sayings: 'The poor,' he declares in Mark's gospel, 'will always be with you.'

So if that is the case, why put in any effort to help them? As blogger Dan Martin has written: 'I have run across this verse abused by conservative Christians, who were objecting to liberal Christians' attempts to actually fight poverty, particularly using political means. The argument seems to go something to the effect that if Jesus said we'd never get rid of the poor, it's foolish for the liberals to try.'

Indeed, in 2014, Rick Perry, who is now US Secretary of Energy, was asked while Governor of Texas about the widening gap between rich and poor in his state. 'Biblically, the poor are always going to be with us in some form or fashion,' he told The Washington Post. For Perry, increasing inequality between the wealthiest and poorest Texans was simply not an issue. He declared: 'We don't grapple with that here.'

However, as the saying goes, 'a text without a context is a pretext'. So we have to look at the background to these words of Jesus in Mark 14v7, which we have now reached as we continue our fortnightly pilgrimage through that gospel. In fact, a bit of basic research shows that Jesus is referring back to Old Testament teaching. And specifically, he is alluding to Deuteronomy 15v11, which says: 'For there will never cease to be poor in the land. Therefore I command you, "You shall open wide your hand to... the needy and to the poor, in your land".'

That same Old Testament section also declares: 'If there is anyone in need... do not be hard-hearted or tight-fisted... Be careful that you do not entertain a mean thought... Give liberally and be ungrudging when you do so...' (15v7-10).

So it turns out that Jesus is saying the exact opposite of what some people think. Rather than making a somewhat fatalistic pronouncement that since there will always be poor people, we might as well give up helping them, Jesus is actually referring to a Biblical command to be generous in assisting them.

And there's a more immediate context, too. In Mark's gospel, the situation in which Jesus utters his words about the poor 'being always with you' is at a meal where an unnamed woman has just burst in and unexpectedly anointed Jesus with what Mark calls a 'very costly' perfume. She loves Christ and she wants to make it known.

As some around the dinner table start making disapproving noises about her (in their eyes) excessive devotion, Jesus makes it clear that in fact she has done something beautiful. And so he then goes on to say: 'You always have the poor with you, and you can show kindness to them whenever you wish. But you will not always have me. She has done what she could; she has anointed my body beforehand for its burial,' (Mark 14v7-8).

It was common practice to anoint dead bodies of people before they were buried. There was only one exception – if they had been executed as criminals. And that was precisely what was to happen to Jesus, who was about to be arrested on trumped up charges and then executed as a common criminal. So in the normal course of events his body would not have been anointed. Except, now, it was. And though it's doubtful the woman herself understood fully what she was doing, Jesus used what happened to point forward again to the importance of his death.

And so we learn that true discipleship is costly. First of all, to show our loyalty and love for Jesus – as this woman does here – will involve self-sacrifice. We won't be physically pouring jars of expensive perfume over Jesus. But discipleship will cost us money and time; it may well also cost us contempt and lack of understanding from others too.

Secondly, if we take the context of Jesus words about the poor seriously, discipleship will also be costly for us in helping those less well off in our society. For if the poor are always with us, there will always be a need for us to be 'liberal and ungrudging' in our help, as Deuteronomy states. That will take time, energy and money – whether through impromptu acts of kindness, volunteering, charitable donation or taxation.

Finally, we are reminded that the call to love Jesus and help the poor will provoke hostility from many. Even as this unnamed woman lavishly anoints Jesus, religious leaders (v1) and Judas (v10) are plotting to kill him. As Jeremy McQuoid puts it: 'Christ remains the great dividing line in history. You can utterly reject Him, or you can give your all for him. What you must not do is treat the controversial Christ half-heartedly.'

David Baker is a former daily newspaper journalist now working as an Anglican minister in Sussex, England. The Rough Guide to Discipleship is a fortnightly series. Find him on Twitter @Baker_David_A