Luke 13:30 And, behold, there are last which shall be first, and there are first which shall be last.
Let's look at birth order. Cain was before Able. Gen 4:1 And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD.
Gen 4:2 And she again bare his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground.
Gen 4:8 And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.
Gen 4:9 And the LORD said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?
The Lord honored Able above Cain. Cain was a murderer and a liar. Two more brothers born of Isaac, Esau and Jacob. Jacob tricked Esau out of his birthright. Esau despised his birthright, selling it for a bowl of stew. In spiritual terms, there is a natural birth and a spiritual birth. Jesus explains this.
John 3:3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.
John 3:6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
Paul, under the inspiration of God explains this in regard to flesh body and spiritual body. The natural body of flesh is first, the spiritual body is last.
1 Cor 15:44 It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
1 Cor 15:45 And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit.
1 Cor 15:46 Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
1 Cor 15:47 The first man is of the earth, earthy: the second man is the Lord from heaven.
1 Cor 15:49 And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
Consider John the baptist.
Mat 11:11 Verily I say unto you, Among them that are born of women there hath not risen a greater than John the Baptist: notwithstanding he that is least in the kingdom of heaven is greater than he.
How can this be? Those in the kingdom of heaven are spiritual, John had not yet seen the salvation of the cross which had not yet occurred.
In conclusion, the flesh man comes first, but the spiritual man is greater in the kingdom of God. In context, not everyone who does religious things shall be first, even if they are high up in their organization. The least who is redeemed by Jesus is first. Although they may be despised by other religions.