“No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money. - Matthew 6:24
How do we live for God through Christ with all our strength? First we must establish what is meant by "strength".
We have already seen in the introduction to this series that the term translated "strength" or "might" occurs as an adverb or adjective translated something like "very", "much", or "greatly" in almost every other of its near 3oo occurences. The usage here is unique.
We have said that this term seems to be intended to cover any and every kind of resource or choice at our disposal that is not covered by the terms "heart", "soul", or "mind". Thus "strength" is a catch-all term for everything else in our lives. We are called to love God out of the abundance of our life and with all of it to be fully devoted to him.
One implication of this is that there is no single aspect of our existence and life that is not included in the command to love God.
To live for God through Christ with our strength must mean devoting every resource at our disposal to God's purposes. I suppose that if strength had not been included in this command that there may be those who would attempt to divide their devotion (as though devotion could be divided) between two or more separate objects. But our lives are not divisible in this way. We serve something or someone highest of all. We may only have one master, because eventually the demands of one will conflict with those of another. That is why Paul and Jesus say that we must decide whom we will serve (Matt. 6:24; Rom. 6:16). So the metaphor of slavery is apt because we understand how a slave's strength is used in service of the master.
So what kinds of categories should we be thinking about as consider living for God with all our strength? I believe one right approach is to consider categories in our lives in which we tend to treat something as exclusively ours. Then we can move to consider in what way we ought to think about this category as far as living for God in it is concerned.
This includes our wealth. It is easy for us to consider our wealth as ours because, in many cases, we earned it. However, wealth is a kind of strength. As we understand the term "strength" to refer to abundance and strength, it is easy to see that our wealth must also be included. This is to say that the abundance of wealth we have is also to be devoted to God in love. We are called to live for God with our wealth, which ought to cause a shift in our thinking from conceiving of it as "my money" and instead thinking of it as God's money. We are never the true owners of our wealth. We are managers of God's.
This includes our time. We often think of our time in terms of how we want to "spend" it. While it is true that time may be treated as a resource akin to money, it is false to treat time as something which belongs exclusively to us to spend. Time is a resource given to us by God to steward, not to do with what we will. In other words, there is no separation in our lives between "God time" and "me time". All the time I have comes from God and is for God. And to the extent that I have a choice in how to spend that time, it must be spent for God. This means that in all the talk about productivity and time management that is so common today, we do well to make a point of conceiving of them not in terms of our own goals and desires but God's. Yet so often we fail to love God with our strength because we are spending all of it on ourselves. And this is common enough that I frequently have conversations with professing believers who do not spend enough time in Scripture to know how God would have them use the time. Thus reading Scripture is not only a duty, but essential for knowing how we ought to live. We only know how to live for God to the extent that we know him well enough to have an idea of how he would like us to do it.
There is, in short, no part of what belongs to us that is excluded from the command to devote it to the Lord in love, and therefore to live for him with it. The call is comprehensive.
All That We Have
In general, the call to love Yahweh with all our strength amounts to a general call to live for God with all that we have. I say all that we have, because the command regarding heart, soul, and mind relates most closely to what we are.
Perhaps at this point we should ask an interpretive question: is it better to think of "strength" in terms of our bodies specifically rather than what I have said, that we should undersand it as a general catch-all term for everything about our life that is not captured by the other terms? It would be nicely symmetrical for Yahweh to command us to love God, in short, body and soul. This has the effect of capturing our internal life and our outward behavior. However, this is isn't what the text says. And because we have more than one term for the internal life, it would seem that symmetry is not part of the design for the command. Rather, it seems that the thrust of the command is to evoke an effect of overwhelm on the person who captures the all-encompassing nature of the command. By "throwing in" strength, the reader or hearer cannot fail to grasp that this command demands that our love not be relegated to a certain area of our life, but that it define the totality of our identity. The call to love Yahweh in this way is in effect a call to live for God. And it is every bit as total and absolute as Jesus' call to whoever would come after him to take up their cross in order to begin.
As we think of living for God through Christ in terms of our strength, it is worth considering the fact that we are not able in our own strength to live for God. We do it through Christ. And Paul says that it is not him but Christ who lives in him. At the same time, Paul also says that he can do all things through Christ who strengthens him. So if we live in Christ, we live with a strength that God himself provides.