A salvation that rests entirely on what Jesus Christ has done for you is the only kind that saves. You’ve pointed to Romans 10, and that passage stands solid: if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. Nothing else can be added to that without undermining the good news. When the Spirit comes into a life, it is never because we earned him; it is always by the hearing of faith. That is how Abraham was declared righteous. He believed God’s promise, and God credited that faith to him as righteousness. The same is true for you and for anyone seeking him. You come as you are, trusting that Christ’s death and resurrection are enough.
At the same time, genuine faith does not stay hidden. You also mentioned turning from sin and following Jesus in obedience, and that is not a contradiction. It is the fruit that a living faith produces. To say you have faith and then to live as if nothing has changed is to deceive yourself. True belief works, not to secure salvation, but because salvation has already taken root. Repentance and a changed life are the evidence, not the price. Think of it this way: when John the Baptist called for fruit that demonstrates repentance, he wasn’t telling people to clean themselves up first and then come to God. He was describing what a heart that has truly turned looks like. So you begin by confessing Christ and trusting him, and out of that trust flows a new direction. You don’t obey to become saved; you obey because you are saved.
That’s why diving into the Gospels is such sound advice. Starting with John is especially wise, because that book is written so that you might believe that Jesus is the Christ, the Son of God, and that by believing you might have life in his name. As you read, you will see him who is the author and finisher of our faith, the one who learned obedience through suffering and became the source of eternal salvation for everyone who follows him. Faith feeds on the word. It grows as you see his faithfulness displayed page after page.
Don’t be surprised if your trust wavers at times. Even those great in faith had moments of weakness. Abraham stumbled. Elijah ran and hid. Yet the New Testament doesn’t dwell on their lapses; it points to how God upheld them. He is patient with imperfect people. Your standing is not in the strength of your hold on him, but in the strength of his hold on you. Keep looking to Jesus, take him at his word, and let that quiet confidence shape how you walk. The same Spirit who enabled you to believe in the first place will continue the work he began, producing in you the desire and the power to live for him.