In the Westminster Confession of Faith, the divines addressed the nature of our assurance of salvation. While many in our day strive after special signs or think they need a verbal affirmation from God before they'll be assured, we believe that the ordinary use of the means of grace is the greatest source of assurance to us! Why? Because these are the means the Holy Spirit uses to build up our faith and direct our lives! We don't need neon signs or fleeces (see story of Gideon in the book of Judges) - we need the Word of God!
—Westminster Confession of Faith 18.1, 3
Although hypocrites and other unregenerate men may vainly deceive themselves with
false hopes and carnal presumptions of being in the favor of God, and estate of salvation
(which hope of theirs shall perish): yet such as truly believe in the Lord Jesus, and love
him in sincerity, endeavoring to walk in all good conscience before him, may, in this life,
be certainly assured that they are in the state of grace, and may rejoice in the hope of the
glory of God, which hope shall never make them ashamed.
This infallible assurance doth not so belong to the essence of faith, but that a true
believer may wait long, and conflict with many difficulties before he be partaker of it:
yet, being enabled by the Spirit to know the things which are freely given him of God,
he may, without extraordinary revelation, in the right use of ordinary means, attain
thereunto. And therefore it is the duty of everyone to give all diligence to make his call-
ing and election sure, that thereby his heart may be enlarged in peace and joy in the
Holy Ghost, in love and thankfulness to God, and in strength and cheerfulness in the
duties of obedience, the proper fruits of this assurance; so far is it from inclining men to
looseness.