Hi,
It is safe, but the dedication ritual is binding agreement between you and the Gods, it is real, and will be immidiately obvious as such. So, don't do it until you are sure you never want to turn back. If you do it then turn back, father Zeus/God will not punish you, but you will no longer be under him and the Gods and thus have no protection, as you were under the full foot of Xianity, and as I was under Xianity.
Also, the Gods may or may not accept you back if you break your oath and contract with them to be their family. The dedication ritual makes you an initiate in the path to God hood and the path of the Gods. Therefor it also makes you family to God and the Gods.