All believers like Abraham have been fully persuaded and taught by the Holy Spirit that God is able to perform all His pleasure (Eph. 1: 11). God-given faith is altogether persuaded and totally satisfied in the ability of the sovereign God to accomplish all our salvation. David prayed this way, "I will cry unto God most high; unto God that performeth all things for me" (Psalm 57.2). Believers rest in the awesome ability of God, not in any mundane ability of the flesh. We say with the apostle Paul, "We rejoice in Christ Jesus and have no confidence in the flesh" (Phil. 3:3). If we would take a close look at the Word of God we can see that God is able to perform all things for us in salvation.
The disciples asked the Lord Jesus Christ, "Who then can be saved?" He replied, "With men it is impossible, but not with God: for with God all things are possible" (Mark 10: 27). Because of our total ruin in Adam (Rom. 5:12). Because of our sinful condition by nature we are unable to improve our standing before God (Rom. 3: 9-19). But, Jesus Christ became the Surety and Mediator of His people and fully effected salvation for them through His blood and righteousness (2 Cor. 5:21).
There are some people who teach that a man can be saved one day and lost the next. But this sort of teaching is foreign to the Word of God. The believer is kept by the power of God (I Peter 1:5). Jesus Christ gives His sheep eternal life and they shall never perish (John 1O:27-30).
When the apostle Paul was about to leave a group of believers at Ephesus; he strongly commended them to God, and the word of His grace, which is able to build them up. The Word of God is the children's bread upon which we grow and are nourished with spiritual strength (1 Peter 2.2).
The Lord Jesus Christ by His infinite sacrifice for His people subdued all their sins (Heb. 9:26). Therefore, one day soon, He will change our vile body and fashion it like unto His glorious body.