49 Until the Lord shall come in His majesty, and all the angels with Him and death being destroyed, all things are subject to Him, some of His disciples are exiles on earth, some having died are purified, and others are in glory beholding "clearly God Himself triune and one, as He is"; but all in various ways and degrees are in communion in the same charity of God and neighbor and all sing the same hymn of glory to our God. For all who are in Christ, having His Spirit, form one Church and cleave together in Him. Therefore the union of the wayfarers with the brethren who have gone to sleep in the peace of Christ is not in the least weakened or interrupted, but on the contrary, according to the perpetual faith of the Church, is strengthened by communication of spiritual goods. For by reason of the fact that those in heaven are more closely united with Christ, they establish the whole Church more firmly in holiness, lend nobility to the worship which the Church offers to God here on earth and in many ways contribute to its greater edification.(269) For after they have been received into their heavenly home and are present to the Lord, through Him and with Him and in Him they do not cease to intercede with the Father for us, showing forth the merits which they won on earth through the one Mediator between God and man, serving God in all things and filling up in their flesh those things which are lacking of the sufferings of Christ for His Body which is the Church.(272) Thus by their brotherly interest our weakness is greatly strengthened.
Source: Lumen Gentium (Vatican.va)