Creationists dont pretend that any knowledge, science included, can be pursued without presuppositions (i.e., prior religious/philosophical beliefs). Creationists affirm that creation cannot ultimately be divorced from the Bible any more than evolution can ultimately be divorced from its naturalistic starting point that excludes divine creation a priori.
Sarfati J., "Evolution and Creation, Science and Religion, Facts and Bias" First published in Refuting Evolution.
http://www.creationontheweb.com/content/view/3830/
What part do presuppositions play in formulating scientific theories of origins.