2. It is _necessary_, for "without holiness no man shall see the Lord." Sometime, somehow, somewhere, sin must go out of our hearts--all sin--or we cannot go into Heaven. Sin would spoil Heaven just as it spoils earth; just as it spoils the peace of hearts and homes, of families and neighbourhoods and nations here. Why God in His wisdom allows sin in the world, I do not know, I cannot understand. But this I understand: that He has one world into which He will not let sin enter. He has notified us in advance that no sin, nothing that defiles, can enter Heaven, can mar the blessedness of that holy place. "Who shall ascend into the hill of the Lord? or who shall stand in His holy place? He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully" We must get rid of sin to get into Heaven, to enjoy the full favour of God. It is necessary. "Choose I must, and soon must choose Holiness, or Heaven lose. If what Heaven loves I hate, Shut for me is Heaven's gate! "Endless sin means endless woe; Into endless sin I go If my soul, from reason rent, Takes from sin its final bent. "As the stream its channel grooves, And within that channel moves; So does habit's deepest tide Groove its bed and there abide. "Light obeyed increaseth light; Light resisted bringeth night; Who shall give me will to choose If the love of light I lose? "Speed, my soul, this instant yield; Let the light its sceptre wield. While thy God prolongs His grace, Haste thee to His holy face." 3. This purification from sin is _promised_. Nothing can be plainer than the promise of God on this point. "Then will I sprinkle clean water upon you, and ye shall be clean; from _all_ your filthiness and from _all_ your idols will I cleanse you." When all is removed, nothing remains. When all filthiness and all idols are taken away, none are left. "But where sin abounded, grace did much more abound; that as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord" (Romans v. 20, 21). Grace reigns, not through sin, but "through righteousness" which has expelled sin. Grace brings in righteousness and sin goes out. "If we walk in the light, as He is in the light, we have fellowship one with another, and the blood of Jesus Christ His Son cleanseth us from all sin" (1 John i. 7). Hallelujah! "Being then made free from sin, ye became the servants of righteousness" (Romans vi. 18). These are sample promises and assurances any one of which is sufficient to encourage us to believe that our Heavenly Father will save us from all sin, if we meet His conditions.