Gal 6:14, Phil 3:3, 1 Jn 5:20, 1 Cor 1:31, 2 Cor 10:17
In the Old Testament, God told the Israelites not to boast about themselves, but to boast about knowing God. (Jeremiah 9:23-24)
Jeremiah 9:23 Thus saith the Lord, Let not the wise man glory in his wisdom, neither let the mighty man glory in his might, let not the rich man glory in his riches: 24 But let him that glorieth glory in this, that he understandeth and knoweth me, that I am the Lord which exercise lovingkindness, judgment, and righteousness, in the earth: for in these things I delight, saith the Lord.
We have nothing to boast about except in the cross of the Lord Jesus Christ. (Gal 6:14, Phil 3:3, 1 Cor 1:31, 2 Cor 10:17)
Gal 6:14 But God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world.
Phil 3:3 For we are the circumcision, which worship God in the spirit, and rejoice in Christ Jesus, and have no confidence in the flesh.
1 Cor 1:31 That, according as it is written, He that glorieth, let him glory in the Lord.
2 Cor 10:17 But he that glorieth, let him glory in the Lord.
Christ made us to know God. Also, Christ Jesus is the true God. (1 John 5:20)
1 John 5:20 And we know that the Son of God is come, and hath given us an understanding, that we may know him that is true, and we are in him that is true, even in his Son Jesus Christ. This is the true God, and eternal life.