There is no contradiction here, if one bothers to read the full verses of Genesis 6:19 and Genesis 7:2-3. To begin, Genesis 7:2-3 does not say that Noah brought 7 pairs of each type of animal onto the ark. It only says that Noah brought 7 pairs of clean animals and fowls onto the ark. In fact, verse 2 specifically says that Noah brought only one pair of each type of unclean animals onto the ark.
Further, this claim to a contradiction leaves off a very important clause of Genesis 6:19. “And of every living thing of all flesh, two of every sort shalt thou bring into the ark, TO KEEP THEM ALIVE WITH THEE: they shall be male and female.”
The point is that Genesis 6:19 specifically says that Noah was to bring one pair of every type of animals to KEEP THEM ALIVE (i.e. so that their types could be propagated after the flood). Genesis 7:2-3 includes further instructions that Noah was to bring on ADDITIONAL clean animals for the purpose of the sacrifices important in Old Testament religion. In Genesis 8:20, after the flood, Noah built an altar and sacrificed of every clean beast and fowl unto the LORD. Thus, we see that the purpose of these extra animals was for Noah and his family to be able to keep the sacrifices utilised in Old Testament times. Obviously, if these extra clean animals were used as sacrifices, then they couldn't have been on the ark for the purpose of “keeping them alive”. They were there for sacrificial purposes.
Thus, we see that there is no contradiction between Genesis 6:19, which details the taking of one pair of every animal type so as to propagate the species, and Genesis 7:2-3, which details the taking on of additional clean animals who were NOT to be “kept alive”, in addition to the single pair which was for the purpose of propagating the clean kinds of animals.
Editor's Note: Some sceptics will acknowledge the fact that only some of the animals were brought on in groups of seven, yet still attempt to build a contradiction by ignoring the facts mentioned above about the extra clean animals not being brought onto the ark for the purposes of being kept alive for the propagation of their kinds. Hence, their arguments for biblical inconsistency still fold.