Jesus came through the "seed of the woman". Women do not carry "seed", men do. Mary was a virgin - the "seed of the woman" was impregnated via the Holy Spirit - not a MAN. Therefore, Jesus was pure, spotless, without blemish, the Lamb of God. This is what Hebrews 2:17 - "as the children are partakers of flesh and blood, he also himself likewise took part of the same" . . . . the same what? flesh and blood. He took part of flesh and blood so "that through death he might destroy him that had the power of death".
He was made like unto his brethren in that he was tempted just as we are tempted. Adam had no sin nature UNTIL HE SINNED, he was tempted and he failed . . . Jesus had no sin nature and although he "suffered being tempted" . . . . For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. . . he was without sin - he did not fall into temptation because he had perfect faith in his Father and by his free will choices to trust God, lived a sinless life, always doing the will of the Father.
When God asked the Israelites to pick out a "lamb without blemish", he meant one that was sound, wholesome, unimpaired, innocent, having integrity; whole, sound, healthful; complete . . . Jesus had to be "unimpaired, innocent" - one is not "unimpaired or innocent" when one has a "fallen nature". What do you think would have happened if a household of Israelites chose a lamb that was not "whole, unimpaired, sound, or healthful" and put that blood upon their doorpost? They would not have been "passed over" but destroyed. . . . So if Jesus had a "fallen sinful nature", we do not have a Savior, we are not redeemed . . .