Yes, we only gain salvation by believing in Jesus. This is it. We don't have to be good enough to believe in Him. We don't have to get our act together before we make Him our Savior. We simply believe. Then what? We walk.
But if we WALK in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
John 1:7
That ye might WALK worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God.
Colossians 1:10
And WALK in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour.
Ephesians 5:2
The Bible even says that disobedient husbands may be won by their wives walk, their lifestyle. {I Peter 3:1}
Therefore, we must WALK according to what we believe. God doesn't want us just to believe but to have a transformed life by renewing our minds with His Truth since His Word is living and active. As soon as we believe, His Spirit indwells us and enables us to WALK in love and to WALK in Him. If there's no change in us after we believe, there's no belief. Our behavior flows out from our beliefs. We adorn His Word when we WALK in obedience to it and we blaspheme it when we WALK in disobedience.
Does this mean we are perfect? Perfect in Christ, yes, since He fulfilled the Law and paid the penalty for our sins. We are freed from sin and damnation. However, we aren't perfect while living on this earth, but our lives should be looking different than those around you. People should be able to see Jesus living inside of us. We should be growing kinder, more patient, more loving and forgiving, more meek and gentle, more like Jesus.
Examine your life, the Bible says, to make sure you are in the faith, NOT to see how much sin is in your life but how much you believe. Do you believe you have been purged from your sins? Do you believe you are a child of the Most High and dearly loved? Do you believe you can do ALL things through Christ who strengthens you? Then walk in Truth and in love. You can do it.