We cannot let unbelief keep us from hope. That would be playing right into the devil's hand... to forsake the gospel, the brethren, and the hope of eternal life because we feel bad. It is unacceptable, irresponsible, and totally beneath the glorious grace of our God– "For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's (I Cor 6:20)."
I recognize, somewhat, that you and I are incapable of fulfilling any of these responsibilities in ourselves. But, that is why salvation is by grace and our faith is in Him. We trust Him to take us, who are nothings, and fulfill His promises and commands. Whatever our responsibilities are, we are covered with Christ's precious blood and shall be enabled to fulfill them–"Faithful is he that calleth you, who also will do it (I Thess 5:24)."
When Hagar and Ishmael were cast out of Abraham's house, it is a picture of salvation and/or the strengthening of a saint. They left with a little cruse of water. When it was dried up, Hagar cast Ishmael in the bushes and went off because she didn't want to hear him die. But the Lord spoke to her out of heaven saying, "What aileth thee, Hagar? Fear not; for God hath heard the voice of the lad where he is (Gen 21:17)." And, that is exactly how it is. When we are nothing, when our strength is dried up and gone, GOD HEARS US EXACTLY WHERE WE ARE. When we are at the place where we think everything is lost, I cannot save myself, and my hope of being saved is well-nigh gone, our God hears and provides His Son. He opened Hagar's eyes, and she saw a Fountain (vs19).
And, so it is with Christ. He got the victory, and now He gives it to us (I Cor 15:55-57). He got the victory over sin by the shedding of His precious blood. He remained faithful and obedient unto death. And, He gives US the victory, which is redemption through His blood–the forgiveness of sins. He got the victory over temptation. Even when Satan troubled Him sore, He remained faithful to God our Father and conquered. Therefore, when you and I are weak, and totally unable to withstand temptation, which is really all the time, He gives us the power to worship none other (Matt 4:10 & 16:21-23).
And, if you are tempted sore, and if your heart has wandered so much that you cannot recover yourself from lusts and compromise, take with you the blessed petition of Ps 119:176, "I have gone astray like a lost sheep; seek thy servant; for I do not forget thy commandments." Our God, the true and the Living God, is a God who saves us where we are.