Romans 5:10 (NKJV)
For if when we were enemies we were reconciled to God through the death of His Son, much more, having been reconciled, we shall be saved by His life.
This verse has many ideas in it. The main thrust is the argument from the greater to the lesser. It is incredible that God would send His Son to die for us, his enemies. Now that I am reconciled to Him, no longer an enemy, requiring his death to do that part; why would he not even more (much more!) desire to keep me saved by his resurrected life?
My pastor speaks of three tenses of salvation. Salvation begins by becoming saved from the penalty of sin. This is a one time event that occurs when faith is placed in Jesus Christ. Salvation continues for the remainder of life in which a person is progressively saved from the power of sin. Finally at the death, a saint is delivered from the very presence of sin. In theological terms this would be first, justification, which Paul describes in this verse as reconciliation. Secondly, the process continues and is called sanctification which means becoming "set apart" or made holy. The theological term for the final stage of salvation occurring upon entering heaven is glorification, when we are made like Christ.
Forgiveness of sins is a wonderful feeling but it is just the beginning of a changed life. Not only did Christ die for us, He also lives for us!
Hebrews 7:25 (NKJV)
Therefore He is also able to save to the uttermost those who come to God through Him, since He always lives to make intercession for them