It's a both thing. It is not just God or just us it is always God and us. It is God's grace and our will. If we love him we will bare good fruit. Remember St. Pual if you have faith that can move mountains but dont have love it (your faith) comes to nothing. Faith , hope and charity (love) and the greatest is love!
Discussion
A criminal, unbaptized and justly being put to death, can enter Heaven by accepting Christ in his heart and proclaiming Him the Son of God.
Don't forget about the thief on the cross.
