There will be many at Christ's right hand in the last day. The saints gathered from North and South, and East and West, will be "a multitude that no man can number." (Rev. vii. 9.) The song of victory that will burst from their mouths, when their redemption is at length complete, will be a glorious song indeed. It will be far above the noise of many waters, and of mighty thunders. But there will be no discord in that song. They that sing will sing with one heart as well as one voice. Their experience will be one and the same. All will have believed. All will have been washed in the blood of Christ. All will have been born again. All will have prayed. Yes, we must pray on earth, or we shall never praise in heaven. We must go through the school of prayer, or we shall never be fit for the holiday of praise. In short, to be prayerless is to be without God,--without Christ,--without grace,--without hope,--and without heaven. It is to be in the road to hell. II. In the second place, _a habit of prayer is one of the surest marks of a true Christian_. All the children of God on earth are alike in this respect. From the moment there is any life and reality about their religion, they pray. Just as the first sign of life in an infant when born into the world, is the act of breathing, so the first act of men and women when they are born again, is _praying_. This is one of the common marks of all the elect of God: "They cry unto Him day and night." (Luke xviii. 1.) The Holy Spirit, who makes them new creatures, works in them the feeling of adoption, and makes them cry, "Abba, Father." (Rom. viii. 15.) The Lord Jesus, when He quickens them, gives them a voice and a tongue, and says to them, "Be dumb no more." God has no dumb children. It is as much a part of their new nature to pray, as it is of a child to cry. They see their need of mercy and grace. They feel their emptiness and weakness. They cannot do otherwise than they do. They _must_ pray. I have looked carefully over the lives of God's saints in the Bible. I cannot find one of whose history much is told us, from Genesis to Revelation, who was not a man of prayer. I find it mentioned as a characteristic of the godly, that "they call on the Father," that "they call on the name of the Lord Jesus Christ." I find it recorded as a characteristic of the wicked, that "they call not upon the Lord." (1 Peter i. 17; 1 Cor. i. 2; Psalm xiv. 4.) I have read the lives of many eminent Christians who have been on earth since the Bible days. Some of them, I see, were rich, and some poor. Some were learned, and some unlearned. Some of them were Episcopalians, some Presbyterians, some Baptists, some Independents. Some were Calvinists, and some Arminians. Some have loved to use a liturgy, and some to use none. But one thing, I see, they all had in common. They have all been _men of prayer_.