Unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven. (Matthew 5:20)
In the Name + of Jesus. Amen. If you could earn your salvation, you would need to try a lot harder than you have so far. Indeed, you're going to have to start life completely over, since you were already conceived and born sinful. That's the point of these words of Jesus: You cannot do enough to enter the kingdom.
Because we're familiar with the Scriptures, we think of the Pharisees as a bunch of hypocrites who were no more righteous than the worst sinners of Jesus' day. However, Jesus is calling for a surface comparison, not judging the heart but merely emphasizing the deeds.
The Pharisees tithed, prayed, read Scripture, and devoted themselves to acting as righteously as possible. They went out of their way to avoid becoming unclean and set firm boundaries so they'd never be accused of working on the Sabbath. And Jesus says, "That's not good enough!"
To save yourself through the Law you must keep it perfectly, "For whoever keeps the whole law but fails in one point has become accountable for all of it" (James 2:10). In the context of Matthew 5, you must be poorer in spirit, more desirous of righteousness, meeker, purer, and more peaceful than anyone has ever been in order to save yourself.
Jesus doesn't give you any wiggle room, either. He says that He came not to abolish the Law but to guarantee that it is accomplished. Perfectly. What can we do if righteousness, meekness, and peacefulness are not ever foremost in our hearts and minds? Self-promotion, self-love, and self-serving (our customary strengths) have no place in the kingdom.
Yet there is hope, for what the Law demands, Jesus did. Rich beyond measure, He became poor for you. From heaven's joy, He came to sorrow with and for you. Almighty, He meekly accepted His death. Hungry and thirsty for righteousness, He always did His Father's will. What He did far exceeded the righteousness of the Pharisees and what He accomplished, the Father credits to you as you believe in Christ. In the Name + of Jesus. Amen.
O keep me watchful, then, and humble; Permit me nevermore to stray. Uphold me when my feet would stumble, And keep me on the narrow way. Fill all my nature with Thy light, O Radiance strong and bright. (Thee Will I Love, My Strength, My Tower, LSB 694:4)