I believe the children of God HAVE eternal life. Not that their flesh has eternal life but that their spirit is eternal. The body that they live in while in this world will die but their spirit is alive forever.
1 Corinthians 15:42-49
42 So also is the resurrection of the dead. The body is sown in corruption, it is raised in incorruption.
43 It is sown in dishonor, it is raised in glory. It is sown in weakness, it is raised in power.
44 It is sown a natural body, it is raised a spiritual body. There is a natural body, and there is a spiritual body.
45 And so it is written, "The first man Adam became a living being." The last Adam became a life-giving spirit.
46 However, the spiritual is not first, but the natural, and afterward the spiritual.
47 The first man was of the earth, made of dust; the second Man is the Lord from heaven.
48 As was the man of dust, so also are those who are made of dust; and as is the heavenly Man, so also are those who are heavenly.
49 And as we have borne the image of the man of dust, we shall also bear the image of the heavenly Man.
NKJV
so also are those who are heavenly --- this is present tense ----- it is not future tense.