I believe you can lose your salvation, but only if you turn your back on HIM and stop believing. I do believe that a person can believe that Christ died for our sins and has no doubt in their heart and be saved and later in life stop believing. The devil is a strong adversary to the human being. It takes constant vigilance on our part not to slip and fall into the devils plan. We can turn our backs on GOD, however HE will never turn his back on us. HE waits patiently for us to find our way back to HIM. It only takes faith the size of a mustard seed to move mountains with GOD's help, that's why we must have faith so we can help God help us.