Because Heaven is. Here are two sections from the Revelation of Jesus to John. Pay close attention to what the activity and exercise of Heaven will be.
Then I saw in the right hand of him who was seated on the throne a scroll written within and on the back, sealed with seven seals. And I saw a mighty angel proclaiming with a loud voice, “Who is worthy to open the scroll and break its seals?” And no one in heaven or on earth or under the earth was able to open the scroll or to look into it, and I began to weep loudly because no one was found worthy to open the scroll or to look into it. And one of the elders said to me, “Weep no more; behold, the Lion of the tribe of Judah, the Root of David, has conquered, so that he can open the scroll and its seven seals.” And between the throne and the four living creatures and among the elders I saw a Lamb standing, as though it had been slain, with seven horns and with seven eyes, which are the seven spirits of God sent out into all the earth. And he went and took the scroll from the right hand of him who was seated on the throne. And when he had taken the scroll, the four living creatures and the twenty-four elders fell down before the Lamb, each holding a harp, and golden bowls full of incense, which are the prayers of the saints. And they sang a new song, saying, “Worthy are you to take the scroll and to open its seals, for you were slain, and by your blood you ransomed people for God from every tribe and language and people and nation, and you have made them a kingdom and priests to our God, and they shall reign on the earth.” Then I looked, and I heard around the throne and the living creatures and the elders the voice of many angels, numbering myriads of myriads and thousands of thousands, saying with a loud voice, “Worthy is the Lamb who was slain, to receive power and wealth and wisdom and might and honor and glory and blessing!” And I heard every creature in heaven and on earth and under the earth and in the sea, and all that is in them, saying, “To him who sits on the throne and to the Lamb be blessing and honor and glory and might forever and ever!” And the four living creatures said, “Amen!” and the elders fell down and worshiped. (Revelation 5 ESV)
And two chapters later…
After this I looked, and behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, and crying out with a loud voice, “Salvation belongs to our God who sits on the throne, and to the Lamb!” And all the angels were standing around the throne and around the elders and the four living creatures, and they fell on their faces before the throne and worshiped God, saying, “Amen! Blessing and glory and wisdom and thanksgiving and honor and power and might be to our God forever and ever! Amen.” Then one of the elders addressed me, saying, “Who are these, clothed in white robes, and from where have they come?” I said to him, “Sir, you know.” And he said to me, “These are the ones coming out of the great tribulation. They have washed their robes and made them white in the blood of the Lamb. “Therefore they are before the throne of God, and serve him day and night in his temple; and he who sits on the throne will shelter them with his presence. They shall hunger no more, neither thirst anymore; the sun shall not strike them, nor any scorching heat. For the Lamb in the midst of the throne will be their shepherd, and he will guide them to springs of living water, and God will wipe away every tear from their eyes.” (Revelation 7:9-17 ESV)
The gospel, the good news about God in Christ saving sinners for His glory, has often been posited as the ABCs of Christianity. Just like the regular alphabet, we have been encouraged to move past the elementary principles of the death, burial and resurrection of the Lord Jesus. Brothers and sisters the gospel is for all of life. The gospel is what we look to and trust for our justification. The gospel is the power of God unto sanctification, as we act the miracle sovereignly wrought by God, purchased by the death of Christ on our behalf.
If you move past the gospel, you are becoming less mature not more mature. The mark of Christian maturity is a growing awareness and delight in the cross of Christ. Even as you grow in actual holiness, you see all the more your need for the holiness of Christ to be received by faith. The gospel animates us to hate sin and pursue righteousness, because the work is finished. You will not overcome sin but white-knuckling it. The sin-destroying pleasure of seeing Christ in the gospel is the only way to grow in grace. Fruit is produced by root; sanctification flows from justification. But both twin graces have their source in the sovereign love of God who put forth Christ as a propitiation for our sins (Ro 3:21-26).
The whole point is Jesus. All things are by Him, for Him, through Him and to Him (Col 1:16; Ro 11:36). When we rush past Christ and Him crucified (something Paul was clear that we would not do) we miss the point. We come to the Bible to know Christ, putting no confidence in the flesh but drawing near based on a righteousness that depends on faith (Phil 3:8-9). We do not come to the Bible, primarily, for tips on living or marriage or social justice or anything like that. We open the book to know God and enjoy God. The only way we can enjoy God is the sin-bearing Substitute, Jesus. We have been saved to savor. We savor when we are enabled to see, again and again, the glory of God in the face of Jesus Christ (2 Cor 3:18).
So friend, do not move past the gospel. We are often told to most past those old, tired doctrines. “What we need today are deeds, not creeds.” Blasphemy! If you remove the latter you will lose the former. The call of Christianity is not primarily to do but to trust in what is done. Not so much to be transformed, first, but to behold the glories of Christ, to turn from the fleeing joys of sin to the surpassing worth of Christ.
Timothy was facing the same temptation in Ephesus. Like many of us, he was timid. False teachers were arising, teaching false things about the gospel and gospel implications. They were fresh, new and vain. Paul encourages Timothy in 2 Timothy 3:15-17 to continue in the things he had been taught. Timothy knew the Scriptures that were able to make him wise unto salvation from an early age. 2 Timothy 1 tells us that his mother and grandmother had earnestly taught him the gospel. Paul, his mentor, had entrusted him the same gospel of justification by faith that the saints have had since Abraham, now fully realized after the ascension of Christ. Paul reminds Timothy that novelty is no real virtue in the Christian life. Indeed, it is the dwelling on those things of first importance that is really profound. Keep the main thing the main thing, in other words. And the effect is telling. The false teaching breeds only enmity and strife. True gospel produces holiness and affections for God.
Do you wish to be useful in ministry? Do you want your own heart to sing with exuberant joy? Stick with the gospel and its many radical implications. You will never get tired of singing, “Jesus paid it all.” Because that fountain filled with blood will never run dry, its power to save being praised by all the ransom church of God, saved to sin no more! Speak O Lord, and drive us again and again to that sweet and aweful place.