You ask how God can love those whom He can save but instead predestine them to eternal suffering.I would like to ask the same question of you? If God knows in advance(before creation)that a certain portion of mankind will ultimately reject Him,then how can God still create these people and be said to 'sincerely'love them?Here we have God creating people whom He knows will reject Him and end up forever in Hell.How can God be said to sincerely love such people? God must have created them simply to destroy them,and we can derive this conclusion without appealing to any destinctively Calvinistic premises.Knowing beforehand that they will reject Him,by then creating them God effectively 'predestines'them to Hell;i.e. ensures that they will actually go there.If God's sovereign determination and man's free choice is a problem for Calvinists it is also a problem for anyone that holds to God's foreknowledge of all that is to come to pass.It is a problem associated with any kind of theism that posits a personal,all knowing,all powerful God. Luther put it well;"God wills what He foreknows and God foreknows what He wills."