I put my trust in GOD to keep me based on Ephesians 2:8,9 'For by grace you have been saved through faith, and that not of yourselves: it is the gift of GOD, not of works, lest anyone should boast.' This right here tells me that my salvation is from GOD, because it's a gift I can't lose it. It's not by anything I have done so if I can't earn it how can I lose it.
True salvation results in a changed life that reflects Jesus in all their thinking and their ways. I don't believe in OSAS, but it doesn't really bother me if a person believes that as long as the evidence of the changed life is seen in them. One of my absolute favorite Christians is Dr. Charles Stanley who believes in OSAS, but is fully submitted to the Holy Spirit and reflects our Lord Jesus. (Yes, I'm talking about him in the present tense even though he went on home to be with Lord already - but he's just asleep - not DEAD dead like dead unbelievers.