We cannot rely on our own merits to get to Heaven. We cannot do enough to earn our eternal salvation. This is because our own works are not good enough. We can only receive salvation by trusting in the Work that God has done through Jesus Christ.
Trusting in our own feeble works is thinking too highly of our own ability. For how many of us are able to honor God by our actions, words, and thoughts every second of every day? We allow ourselves to live under the curse of punishment if we try to uphold the Law by ourselves. Even if we began living perfectly tomorrow, our past failure to uphold the Law would already condemn us. Trusting in our own works also dismisses the Work of Christ. If we could be saved on our own, what need was there for Christ to take upon Himself the curse of sin? Assuming our ability to save ourselves rejects our need for a Savior in Jesus. This is not why Christ died.
Earnest desire to please God by adhering to the Law honors God. But obeying the Law in hopes of earning a chance to arrive in God’s Presence is a tragic thing to do in response to the God Who first came down to us. As we do all that we can to live for God, we must do it out of our growing trust in all that He has done for us.