"Tell me I pray thee wherein thy great strength lieth."
Where lies the secret strength of faith? It lies in the food it feeds on; for faith studies what the promise is--an emanation of divine grace, an overflowing of the great heart of God; and faith says, "My God could not have given this promise, except from love and grace; therefore it is quite certain his Word will be fulfilled." Then faith thinketh, "Who gave this promise?" It considereth not so much its greatness, as, "Who is the author of it?" She remembers that it is God who cannot lie--God omnipotent, God immutable; and therefore concludeth that the promise must be fulfilled; and forward she advances in this firm conviction. She remembereth,why the promise was given,--namely, for God's glory, and she feels perfectly sure that God's glory is safe, that he will never stain his own escutcheon, nor mar the lustre of his own crown; and therefore the promise must and will stand. Then faith also considereth the amazing work of Christ as being a clear proof of the Father's intention to fulfil his word. "He that spared not his own Son, but freely delivered him up for us all, how shall he not with him also freely give us all things?" Moreover faith looks back upon the past, for her battles have strengthened her, and her victories have given her courage. She remembers that God never has failed her; nay, that he never did once fail any of his children. She recollecteth times of great peril, when deliverance came; hours of awful need, when as her day her strength was found, and she cries, "No, I never will be led to think that he can change and leave his servant now. Hitherto the Lord hath helped me, and he will help me still." Thus faith views each promise in its connection with the promise-giver, and, because she does so, can with assurance say, "Surely goodness and mercy shall follow me all the days of my life!"
"Lead me in thy truth, and teach me: for thou art the God of my salvation; on thee do I wait all the day."
When the believer has begun with trembling feet to walk in the way of the Lord, he asks to be still led onward like a little child upheld by its parent's helping hand, and he craves to be further instructed in the alphabet of truth. Experimental teaching is the burden of this prayer. David knew much, but he felt his ignorance, and desired to be still in the Lord's school: four times over in two verses he applies for a scholarship in the college of grace. It were well for many professors if instead of following their own devices, and cutting out new paths of thought for themselves, they would enquire for the good old ways of God's own truth, and beseech the Holy Ghost to give them sanctified understandings and teachable spirits. "For thou art the God of my salvation." The Three-One Jehovah is the Author and Perfecter of salvation to his people. Reader, is he the God of your salvation? Do you find in the Father's election, in the Son's atonement, and in the Spirit's quickening, all the grounds of your eternal hopes? If so, you may use this as an argument for obtaining further blessings; if the Lord has ordained to save you, surely he will not refuse to instruct you in his ways. It is a happy thing when we can address the Lord with the confidence which David here manifests, it gives us great power in prayer, and comfort in trial. "On thee do I wait all the day." Patience is the fair handmaid and daughter of faith; we cheerfully wait when we are certain that we shall not wait in vain. It is our duty and our privilege to wait upon the Lord in service, in worship, in expectancy, in trust all the days of our life. Our faith will be tried faith, and if it be of the true kind, it will bear continued trial without yielding. We shall not grow weary of waiting upon God if we remember how long and how graciously he once waited for us.