15:1 Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, 2 by which also you are saved, if you hold fast that word which I preached to you—unless you believed in vain.
3 For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, 4 and that He was buried, and that He rose again the third day according to the Scriptures.
How easily and quickly we can get off track. Do you remember how this letter to the Corinthians began way back in chapter 1? I know that was three months ago now but I hope you haven't forgotten. I'm certain Paul never took three months to write it. It would be reasonable to assume he wrote it in a single day. But, moreover, now, however etc... - no matter how you translate that word Paul uses to begin chapter 15 it has the definite idea of "Let's get back on track, let's get back to what really matters."
Paul began this letter to the church in Corinth affirming over and over that they were saints, that they were in Christ, that they were (in Christian lingo) saved.
Then he spends 12 chapters addressing all the problems, describing a church with so many issues that one could wonder how they could ever be saved. Now he is saying "Let's get back to what is really important, let's get back to the basics, let's get back to where we started."
"But brothers I declare to you (again) the good news that I preached to you (already). You already received it and you are standing in the Good News now, by which you are also (being) saved, if you hold fast to the Good News, otherwise you believed in vain." The Greek verb tense clearly indicates process. They are in the process of being saved by having received the Good News.
If you get nothing else from anything I have ever written please pay attention to this. In chapter one Paul emphatically and repeatedly told the church in Corinth that were saints, sanctified, saved. Now he is saying they are being saved. Is that a contradiction? It sounds like one. How can I be full height and still be growing? How can I be at my destination and still be on the journey? How can I be graduated and still in school?
Again Paul began this letter affirming their salvation and now after chapters of addressing issues he says they are in the process of being saved. Well which is it?
It's both. Saved literally means healed. These believers are both healed and being healed. They are completely healed in the sense that when they surrendered their lives to Jesus and believed in Him as their Saviour and Lord, He took their place. All accusations made against them by Satan were redirected at Jesus and in Him there was no fault to be found. However in real time they are still a mess. Nothing has changed except that they have given themselves and their mess into His hands. It was then that the effects of the Good News began their healing process.
The same is true for us. The moment we choose Jesus we are completely secure in Him. We begin the healing process, we are still a mess, but the difference is our mess is covered by the life of Jesus. The only thing we can do to be lost after that is to stop believing, to take our lives and our mess back into our own hands. Jesus took our sins. They were buried with Him. If we trust our mess to Him we are both saved and being saved, healed and being healed. It's called Good News for a reason. He is the Good News. Don't turn back ever no matter how messy the mess. All you'll have then is the mess with no hope of healing at all and no Saviour to cover you with His grace.