In the NT, salvation has two elements — salvation in this age and salvation in the next age. It’s the same salvation, but its impact is felt at two different times.
Perhaps the classic expression of salvation in this age is found in the Lord’s Prayer —
(Mat 6:9-10 NIV) 9 “This, then, is how you should pray: ‘Our Father in heaven, hallowed be your name, 10 your kingdom come, your will be done, on earth as it is in heaven.'”
This is just the beginning of the prayer, of course. I think the NIV (along with NET Bible) is right in treating this as a single sentence. As a result, “on earth as it is in heaven” modifies all three petitions: That God’s name be hallowed (be considered holy), that God’s kingdom comes, and that God’s will be done. That is, the prayer is —
May your name be considered holy, on earth as it is in heaven.
May your kingdom come, on earth as it is in heaven.
May your will be done, on earth as it is in heaven.
These are overlapping concepts, very typical of Hebrew poetry. The prayer is that the people of the earth submit to God’s rule, considering him holy and therefore doing his will and bringing his kingdom — on earth as it is in heaven.
Where else do we read about salvation in this age? Well, I would start in the Sermon on the Mount, especially —
(Mat 5:43-48 ESV) “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, Love your enemies and pray for those who persecute you, 45 so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 And if you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? 48 You therefore must be perfect, as your heavenly Father is perfect.”
In this life, in this age, Jesus calls us to be “perfect, as [our] heavenly Father is perfect.” And we do this by being like God when he makes it rain on the just and the unjust. It’s doing good for both good and bad, friends and enemies, believers and unbelievers.
A parallel and very important passage is Rom 12, which ends —
(Rom 12:18-21 ESV) 18 If possible, so far as it depends on you, live peaceably with all. 19 Beloved, never avenge yourselves, but leave it to the wrath of God, for it is written, “Vengeance is mine, I will repay, says the Lord.” 20 To the contrary, “if your enemy is hungry, feed him; if he is thirsty, give him something to drink; for by so doing you will heap burning coals on his head.” 21 Do not be overcome by evil, but overcome evil with good.
Up to this point, Paul’s instructions in Rom 12 dealt largely with relationships within the church. But as he reaches the end of the chapter, Paul speaks of how we treat our enemies — obviously emulating the words of Jesus. “Feed him.” “Give him something to drink.” “Overcome evil with good.”
In this age, God’s will is done and his kingdom comes when we feed our enemies — in the name of Jesus.
It’s not enough to do good, as merely doing good doesn’t cause God’s name to be hallowed. It doesn’t encourage others to also do God’s will. It doesn’t extend the boundaries of the Kingdom. We must do good in the name of Jesus. And it must be an other-worldly kind of good — good for our enemies — the kind of good that can only come from God.