Because It's Still Called 'Today'

I’m currently reading through O. Palmer Robertson’s short little book, God’s People in the Wilderness. It is tying in well with the reading I am doing on the Parable of the Ten Virgins. The premise of his book is that “For the writer of the Hebrews, the church of today finds its most proper definition in terms of the historical experience of the old covenant people of God ‘in the wilderness’ during the days of Moses” (8).
A little over halfway into the book, Robertson uses a phrase that I’ve probably read or heard numerous times, but it has just stuck out to me with a new significance: “participate in God’s promises” (75). It sounds simple enough, but I think this is such a good description of the Christian life. And when you think of it in terms of God’s people in the wilderness, you see how participating can be both exciting and scary. It is wonderful to receive God’s promises, but hard to hold fast to them.
But that is exactly what the writer to the Hebrews bids us to do. And he gives us a sense of urgency by quoting from Psalm 95. We are called out of our sin and into Christ’s righteousness. We are promised rest in Christ now, as well as a Sabbath rest that is to come. But the same words David uses to exhort his generation to participate in these promises are used by the writer of the Hebrews to his own generation: “Today, if you hear his voice, do not harden your hearts as in the rebellion, on the day of testing in the wilderness…” (Heb. 3:7-8).
Isn’t that a powerful word? It not only connects the wilderness generation to David’s and the generation from Hebrews, but ours as well! “The gap between Israel’s wilderness experience which they had undergone over a thousand years earlier is bridged instantly and dramatically by a revitalization of the ‘Today’ of the psalmist” (67).
Robertson highlights the admonitions in Hebrews that lay out how to participate in God’s promises:
Heb. 3:8,15; 4:7: Since we hear God’s voice in his Word, we aren’t to become hard-hearted like the Israelites in the wilderness.
Heb. 3:12,13: “As long as it is called ‘today,’” the church is to exhort one another. Unlike God’s people in the wilderness, we need to take our duty to one another serious.
Heb. 4:1,2: We are to be united by faith, with a godly fear that we could fail to enter God’s rest like that rebellious generation.
Heb. 4:11: We are united in Christ and we have a singular goal to persevere. The horror of the Israelites not entering their rest is a warning for all those who profess Christ. His people will be given a fighting faith to enter his eschatological rest. 
The gap between generations is filled by a single word. We are to strive together as we persevere to enter God’s rest. Today. God’s people participate in his promises together. Not only that, Christ himself is our companion. Roberts explains that we are the new wilderness community. We acknowledge a tension as we live under the new covenant in this age. But as we profess faith in Christ, we will participate in his promises and persevere. He bids us to be prepared for the tension. These exhortations from the writer to the Hebrews help us to be ready for that great day, beginning with today.