Sin nature is not a sin. It is clear that you do not even understand what sin really is.
A sin nature is unclean, nothing unclean enters heaven. Its apparent you dont know what a sin nature is. Thats why the saved partake of a new nature in the new birth 2 Pet 1:4
4 Whereby are given unto us exceeding great and precious promises:
that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
Eph 5:5
For this ye know, that no whoremonger,
nor unclean person, nor covetous man, who is an idolater, hath any inheritance in the kingdom of Christ and of God.
Job 14:4
Who can bring a
clean thing out of an unclean? not one.
Job 15:14
What is man,
that he should be clean? and
he which is born of a woman, that he should be righteous?
Now you say a baby is born righteous, and yet you seem to admit its born with a sin nature which is unholy and unclean.