Please explain me why he (Jesus) rejecting Christians.
This really only applies to the Pentecostal gospel whereby people are born again by water baptism [full immersion] at an age of understanding
(old enough to repent and call on the name of the Lord) and are baptized in the Holy Spirit [with the Bible evidence of speaking forth in tongues,
as Jesus said they would; Mark 16: 15-20].
The entire New Testament is about this, and all the epistles are written to Spirit-filled churches for Spirit-filled Christians. In fact,
Acts and the epistles all define a christian to be such. The epistles in particular are written not only to explain the doctrine of salvation
and what Jesus accomplished - you will also note that there is much teaching of Christian virtues, morality, purpose, how to live and
behave with one another and with worldly people, on preaching the gospel, keeping one's testimony true, charity, not gossiping,
summed up often as "being children of the light" in a world of darkness.
The instituting of the New Testament and the gospel of salvation was brought about at a very high price - the torture and suffering of
our Lord Jesus in human body, along with the excruciatingly painful death of crucifixion. All done for us to believe on the gospel and
to receive the Holy Spirit to enter the Kingdom of God. It behoves us all to value this and to continue in faith and be led of the Spirit.
Unfortunately, [remember the Parable of the sower and the seed] not all who receive this most precious of all gifts in the world
continue on in their spiritual walk, and are led by the Spirit to be overcomers.
Sadly, many Pentecostal Christians let the Spirit lapse and end up indistinguishable from others [no salt, no testimony, no light].
When the flesh or the carnal person increases and snuffs out the light of the gospel then the whole purpose of the Law being written
in their hearts is negated. They practice iniquity; they allow sin and fleshly desires to prevail; their conduct is unbecoming to the Lord
and they are not bearing any fruit.
Matthew 7:19
Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
7:20 Wherefore by their fruits ye shall know them.
7:21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven;
but he that doeth the will of my Father which is in heaven.
7:22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name?
and in thy name have cast out devils? and in thy name done many wonderful works? [Mark 16: 15-20].
Our Lord Jesus is warning Spirit-filled New Testament Christians of the dire consequences of forsaking the gospel, of becoming slothful,
of having put their hand to the plough and turning to look back; of retreating from the gospel to perdition.
The epistles contain many, many warnings against giving up or being deceived to believe false doctrines and the like.
These scriptures will also help support and explain Christ's words in Mathew 7: 13-27
Titus 2:11
For the grace of God that bringeth salvation hath appeared to all men,
2:12 Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world;
2:13 Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ;
2:14 Who gave himself for us,
that he might redeem us from all iniquity, and purify unto himself a peculiar people,
zealous of good works.
1Peter 1:18
Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold,
from your vain conversation received by tradition from your fathers;
1:19 But with the precious blood of Christ, as of a lamb without blemish and without spot:
1:20 Who verily was foreordained before the foundation of the world, but was manifest in these last times for you,
1:21 Who by him do believe in God, that raised him up from the dead, and gave him glory; that your faith and hope might be in God.
1:22
Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren,
see that ye love one another with a pure heart fervently:
1:23
Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever.
1:24 For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away:
1:25 But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you.
Luke 12:46
The lord of that servant will come in a day when he looketh not for him, and at an hour when he is not aware,
and will cut him in sunder, and will appoint him his portion with the unbelievers.
12:47
And that servant, which knew his lord's will, and prepared not himself, neither did according to his will,
shall be beaten with many stripes.
12:48 But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes.
For unto whomsoever much is given, of him shall be much required: and to whom men have committed much,
of him they will ask the more.