Because of the truth that abides in us and will be with us forever.
Once the truth of God has obtained an entrance into the human heart and subdued the whole man to itself, no power, human or infernal, can dislodge it. We entertain it not as a guest but as the master of the house. This is a Christian necessity, and whoever does not believe this is not a Christian.
Those who feel the vital power of the Gospel and know the strength of the Holy Spirit as He opens, applies, and seals the Lord’s Word would rather be torn to pieces than be torn away from the Gospel of their salvation. A thousand mercies are wrapped up in the assurance that the truth will be with us forever, will be our living support, our dying comfort, our rising song, our eternal glory. This is Christian privilege, and without it our faith is worth little. Some truths we outgrow and leave behind, for they are but rudiments and lessons for beginners, but this is not so with divine truth, for though it is sweet food for babies, it is in the highest sense strong meat for men. The painful truth that we are sinners is with us to humble us and make us watchful; the more blessed truth that whoever believes on the Lord Jesus will be saved remains with us as our hope and joy. Experience, far from loosening our hold on the doctrines of grace, has tied us to them more and more firmly; our grounds and motives for believing are now stronger and more numerous than ever, and we have reason to expect that it will remain this way until in death we clasp the Savior in our arms.
Wherever this abiding love of truth can be discovered, we are bound to share in fellowship and to exercise our love. No narrow circle can contain our gracious sympathies; our communion of heart must be as wide as the ocean of grace. Error may be found mingled with truth received; let us go to war with the error but still love the brother for the measure of truth that we see in him. Above all let us love and spread the truth ourselves.