The price to follow Jesus is still the same, everything! The kingdom of God is an all or nothing proposition. There is no middle ground. Only when the kingdom and the person of its King and His cross has no rival in the heart can anything count for anything in terms of eternity. Where this unbending standard is compromised, persecution might be avoided, but the church will no longer be the entity that Paul calls "the pillar and ground of the truth." So what is the church? Where is the church? Before it is the somewhat mixed visible assembly of the elect children of God with all who gather to hear the Word and the kingdom call to radical discipleship, the essence of the church is the indwelling Christ, the divine nature in those who fellowship in that nature and labor to bring its light to the nations.
Before it's greater conquest of the kingdoms of this world, the kingdom is first and foremost where Jesus sits as King on the throne of the heart. When the heart is fully possessed by the High King of Heaven, there is the kingdom of God in its mightiest display of sovereign power. Part of the "mystery of the kingdom" in its present hidden form is that it is no less powerful in its present working as it will be in the day when it will fill all of redeemed creation. Until then, with the exception of certain occasional demonstrations of outward power, the kingdom in its present working must appear to the world as weak and contemptible. This, since at its center is the scandal of the cross, not just as a historic event of redemptive necessity, but in its character as a cruciform way of life where the kingdom is not only entered once, but continually 'being' entered.
Not only when the kingdom began to be preached by John and Jesus, but no less since, "the violent take it by force" (Mt 11:12). Or, as in Luke's version, "every man presses into it" (Lk 16:16). It cannot be otherwise! The straight gate of the kingdom that only few will ever enter will not swing open to casual interest (Mt 7:13). It requires a violence of desperation to enter at all cost (Mk 9:47), and none can presume to have entered if its value and priceless beauty has not far exceeded and eclipsed all else (Mt 13:45-46). The kingdom can brook no rival in the heart. It is all or nothing, and the fruits of the life of the kingdom will demonstrate this radical singleness of eye and heart in the life of it's true heirs (Mt 6:22-23).
Where the conditions of this reality are met in truth, the triumph of the kingdom is as sure and secure in its present mystery form as in its future completion. But this security becomes a treacherous false security if the firm requirements for entering the kingdom have not been met in the real fruits that demonstrate the presence and power of the life of the kingdom, which is the character and nature of the King. Ultimately then, the call to enter the kingdom is the call to regeneration. But if regeneration is not defined and understood by its kingdom context, it risks being greatly perverted.
The call to make every effort to enter the kingdom at all cost becomes the call to be "made partakers of His divine nature". It is union with God's life, which is the life of the new creation, the life of the age to come. It's subjects are no mere servants under its authority and jurisdiction, but but free children who share in the very nature and character of the King through the mysterious miracle of the new birth, also compared to resurrection (Eph 2:1).
Only as Jesus' message of the kingdom in all it's high demand is kept in close, inseparable connection with Paul's gospel of grace can error be avoided. Only be holding both together in faithful tension and and agreement is the true nature of regeneration rightly defined and understood. But to relax or compromise the desperate urgency of entering the kingdom at all cost through submission to its high demands is to pervert the gospel of grace into another gospel, tilting either towards license and casual compromise or the equally deadly trap of legalism. Grace works! The watchword of the Reformation guarding against this common perversion says, "whereas we are justified by faith alone, the faith that justifies is never alone".
Every seed produces after its own kind, and when the seed of the kingdom has germinated into true union with the life of the indwelling divine nature that was most perfectly incarnated in Jesus, the result is that one has now been "born again, not of corruptible seed, but of incorruptible, by the Word of God, which lives and abides forever (1Pet 1:23).
To be born of that seed is also to live and abide and forever, but the cost to enter is the full and free exchange of anything and everything that might compete in loyalty or affection. Jesus warns that only the comparative few will ever enter. The straight gate of the kingdom is the straight gate of true and abiding regeneration, a much greater rarity than many seem willing to consider. Once entered, the cost for continuance is not conveniently lowered. This is why Peter will say, "take diligence to make your calling and election sure".
For the sake of His steadfast covenant with "all the seed", He MUST require that first things be first. This is why when we begin to neglect or forget, as certainly as we are true sons and daughters, we may be sure that we are on our way to the wood shed, till what counts most counts most again. This is why "judgement must begin at the house of God" (1Pet 4:17 with 1Cor 11:22)